UNIVERSITY  OF  CALIFORNIA. 


FROM  THE    LIBRARY  OF 

DR.  JOSEPH    LECONTE. 
GIFT  OF  MRS.  LECONTE. 

No. 


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CONCRETIONS 


KHUM 


THE    CHAMPLAIN   CLAYS 


"I-     TIIK 


CONNECTICUT    VALLEY. 


BY 

J.  M.   ARMS    SHELDON. 

i\ 


WITH   ONE   HUNDRED   AND  SIXTY   ILLUSTRATIONS 


BY 


KATHARINE   PEIRSON   RAMSAY,  L.  R.  MARTIN,  AND   F.  S.  AND   M.  E.  ALLEN. 


BOSTON: 
1900. 


Copyright,  1900, 
BY  J.  M.  ARMS  SHELDON. 


V  N  I  V  LHO  I  TY 

rtj.it 


TO 

MARY    LOWELL    STONE. 


"An  idealist  who  builded, 

A  dreamer  who  wrought." 


98714 


CONTENTS. 


PACK 

I'KKFACE  ..................................  7 

ACKNOWLKIK.MKNT-    ..............................  9 

PART    I. 

OBSERVATIONAL  AND  DESCRIPTIVE  .........................  11 

PART  II. 

HISTORICAL,  EXPERIMENTAL,  AND  THEORETICAL    ....................  18 

(ItMUU     SlMMARY    ..............................  36 

LlTKUATUiK         ................................  39 


43 


PREFACE. 


OHNCE  my  childhood  the  so-called  "claystones"  of  our  valley  have  excited,  first,  my 
curiosity,  and  in  later  days  my  deep  interest  It  has  been,  therefore,  a  keen  delight 
to  picture  in  lasting  form  some  of  the  many  rare  specimens  I  have  unearthed,  and  to 
record  the  observations  made  during  happy  days  upon  the  green  banks  and  the  blue 
\suters  of  the  dear  old  Connecticut. 

THE  AUTHOR. 
DKKKKIKI.I>,  Sept.  1,  1900. 


ACKNOWLEDGMENTS. 


HATEFULLY  but  sadly  I  ;K  knowledge  my  deep  indebtedness  to  the  late  Sir  William 
Dawson  for  bringing  a  portion  of  this  paper  before  the  Montreal  Society  of  Natural 
History,  and  for  the  publication  of  the  same  in  "The  Canadian  Record  of  Science," 
Vol.  IV.,  .Ian.,  1891.     Since  that  time  the  illustrations  have  been  prepared,  the  analyses 
on  p.  2!»  have  been  made,  and  much  new  matter  has  been  added  to  the  text 

I  am  also  under  great  obligations  to  Hon.  George  Sheldon  of  Deerfield  and  to  Miss 
C.  Alice  Baker  of  Cambridge  for  most  generous  help  in  many  directions. 

Through  the  kindness  of  Professor  13.  K.  Emerson  I  have  had  free  access  to  the  large 
collection  of  concretions  in  the  geological  cabinet  of  Amherst  College  which  includes  the 
collection  of  President  Edward  Hitchcock  from  Massachusetts,  and  that  of  Professor 
C.  B.  Adams  from  Vermont. 

To  the  late  Frank  W.  Smith  of  Riverside,  Massachusetts,  I  am  indebted  for  substan- 
tial aid  in  collecting  concretions  on  the  Connecticut. 

My  cordial  thanks  are  also  due  my  valued  assistant,  Mrs.  Edith  E.  Williams  of  Brook- 
line,  for  work  on  the  literature  of  the  subject 

All  the  illustrations  are  original,  and  prepared  expressly  for  this  work.  Unless 
otherwise  stated,  they  are  of  nearly  natural  size,  and  are  figures  of  concretions  in  the 
"  Stone-Arms  Collection,"  which  numbers  fourteen  hundred  specimens. 

Figs.  1,  4,  5,  29,  31,  48,  50,  86,  88,  90-92,  are  drawn  by  Katharine  Peirson  Ramsay, 
and  figs.  3,  11,  49,  93-96  by  L.  R.  Martin,  Assistant  in  the  Museum  of  the  Boston  Society 
of  Natural  History. 

The  photographic  work  has  been  done  by  F.  S.  and  M.  E.  Allen  of  Deerfield ;  to  all 
these  co-workers  I  am  deeply  indebted  for  their  persistent  and  painstaking  efforts. 

Although  the  heliographic  work  of  Messrs.  Hart  and  Von  Arx  of  New  York  is  too 
well  known  to  need  commendation,  I  cannot  forbear  to  express  my  thorough  appreciation 
of  their  skilful  and  extremely  accurate  reproductions. 

J.  M.  ARMS  SHELDON. 


f 

•  HE 

UNIVERSITY 

. 


CONCRETIONS  FROM  THE  CHAMPLAIN  CLAYS 
OF  THE  CONNECTICUT  VALLEY. 


PART  I. 
OBSERVATIONAL  AND  DESCRIPTIVE. 

MY  observations  on  concretions  in  situ  have  been  made  at  various  places  in  the  Con- 
necticut Valley  from  Dummerston,  Vermont,  to  Deerfield,  Massachusetts,  inclu- 
sive, a  distance  of  about  thirty-five  miles.  Besides  these  observations  on  concretions  in 
their  own  abiding-places,  I  have  spent  some  time  upon  a  collection  of  interesting  forms 
from  Windsor  and  Hartford,  Connecticut,  given  by  Miss  Rosa  Bolles  Watson  of  East 
Windsor  Hill,  Connecticut,  and  another  collection  from  Ryegate,  Vermont,  contributed 
liv  John  Ritchie,  Jr.,  of  Boston. 

The  towns  lying  on  the  right  bank  of  the  river  within  the  distance  mentioned  are 
Dummerston,  Brattleboro,  Vernon,  a  small  part  of  Northfield,  Gill,  Greenfield,  and  Deer- 
field  ;  on  the  left  shore  lie  Chesterfield,  Hinsdale,  the  major  part  of  Northfield,  Montague, 
and  Sunderland.  I  have  found  few  clay  beds  exposed  on  the  right  bank,  it  being  either 
green  with  vegetation,  sandy  or  rocky,  but  on  the  left  bank  the  beds  are  numerous. 

It  is  only  in  seasons  of  drought  when  the  Connecticut  is  lowest  that  the  concretion 
collector  is  successful.  The  necessary  equipment  for  collecting  is  a  good  boat,  a  shovel, 
trowel,  and  stout  carving-knife;  rubber  boots;  boxes  and  wrapping  paper  for  packing 
away  the  concretions.  When  exploring  on  the  river,  one  is  first  attracted  by  the  peculiar 
blue  color  of  the  clay,  which  can  be  seen  at  a  considerable  distance.  In  some  places, 
as  between  the  two  ferries,  known  as  Rice's  and  Whitmore's,  on  the  left  bank  in  the 
town  of  Montague,  the  clay  occurs  interstratified  with  sand ;  in  others,  as  on  the  right 
bank  at  Sunderland  bridge,  it  forms  projecting  shelves  into  the  stream  which  are  often 
thickly  strewn  with  concretions  that  have  fallen  from  clay  layers  above  in  times  of  high 
water. 

Again,  as  at  the  mouth  of  Saw  Mill  River,  a  little  stream  that  empties  into  the  Con- 
necticut in  the  town  of  Montague,  the  clay  forms  a  low  wall  which  rises  perpendicularly 


12  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 

from  the  water.  In  the  summer  of  1878  this  wall  was  much  higher  than  at  present ;  it 
was,  in  fact,  one  of  the  finest  exposures  to  be  seen  in  all  the  region.  Stratification  planes 
cut  it  horizontally,  and  joint  planes  obliquely,  while  the  peculiar  bluish  color  presented  a 
striking  contrast  to  the  green  vegetation  above  and  the  sparkling  waters  below.  The 
concretions  were  exposed  only  at  the  water's  edge,  where  there  was  no  possible  way  of 
getting  them  excepting  to  stand  in  the  river  and  dig,  a  trowel  or  stout  carving-knife  being 
the  best  implement  for  the  work. 

In  collecting  concretions  along  the  bank  it  is  better  to  row  up  the  stream  than  down, 
for  in  the  latter  case  the  dislodged  clay  renders  the  water  so  turbid  it  is  impossible  to  see 
the  concretions  that  may  have  been  brought  down  by  the  floods,  and  which  may  show 
new  forms  and  be  guides  to  beds  containing  them  higher  up  the  river. 

It  is  of  the  greatest  importance  that  the  concretions  of  each  clay  bed  be  kept  by 
themselves.  The  word  "bed"  is  here  used  in  the  sense  of  an  exposure  or  outcrop.  The 
beds  are  made  of  many  layers,  and  these  consist  of  many  laminae.  When  the  concre- 
tions of  the  different  beds  are  kept  separate,  the  interesting  fact  is  proved  that  each  clay 
bed  has  a  form  of  concretion  peculiar  to  itself.  One  never  finds,  for  instance,  a  watch- 
shaped  concretion  (like  that  represented  in  PI.  I.  fig.  1)  and  a  cylindrical  or  club-shaped 
concretion  (PI.  I.  fig.  2)  embedded  together,  or  a  botryoidal  mass  (PI.  I.  fig.  3)  and  an 
animal  form  (PI.  I.  fig.  4).  These  are  four  typical  concretions  of  as  many  separate 
beds. 

While  each  bed  has  its  characteristic  form,  this  is  not  attained  with  an  unvarying 
degree  of  perfection.  There  seems  to  be  an  ideal  and  a  struggle  to  attain  it ;  the  result- 
ing concretions  being  more  or  less  perfect  as  the  conditions  are  favorable  or  adverse. 
When  the  conditions  are  favorable  and  constant,  the  typical  form  is  repeated  many  times. 
One  of  the  striking  examples  of  this  fact  was  found  in  a  bed  near  the  west  landing  of 
Whitmore's  ferry  in  the  town  of  Deerfield.  Out  of  twenty-six  specimens  collected,  twenty- 
four  had  the  same  peculiar  crescent-shaped  markings  (PL  I.  fig.  5).  One  of  the  two  ex- 
ceptions I  have  little  doubt  was  the  incipient  form  of  the  others,  and  would  have  grown 
to  be  like  them  in  time  had  it  been  left  undisturbed.  The  other  concretion  was  not  found 
embedded,  but  was  picked  up  from  the  surface  of  the  clay  bed ;  it  was  colored  brown  by 
carbonate  of  iron,  so  that  I  am  confident  it  was  washed  from  some  bed  up  the  river  and 
had  been  exposed  long  enough  to  become  discolored. 

I  have  seen  forty-eight  specimens  from  one  bed  so  similar  it  was  impossible  to  tell 
one  from  another. 

Occasionally,  in  certain  localities,  the  typical  form  is  doubled  or  even  trebled  in  a 
single  specimen.  Eemarkable  examples  of  such  concretions  were  found  in  the  clay  bank 
on  the  north  side  of  Saw  Mill  River,  near  its  mouth.  The  typical  form  (PL  I.  figs.  1,  6) 


(•I-    TIIK   roNM.riliTT    VAI.I.KY.  13 

is  wonderfully  symmetrical.  A  number  of  these  concretions,  nil  remarkably  perfect,  were 
dug  from  the  clay.  A  few  were  found  like  those  of  I'l.  I.  fii;.  7,  \\hcre  it  may  be  that 
two  an-  tpprOAChing  cadi  other  to  form  a  double  concretion.  This  view  is  strengthened 
by  specimens  in  situ  (shown  in  I'l.  1.  fig.  S,  and  I'l.  It.  fig.  It),  recently  taken  from  the 
same  bed.  This  union  is  completed  as  shown  in  I'l.  II.  fig.  10. 

The  upper  connecting  layer  which  lias  just  begun  to  form  in  PI.  II.  fig.  10  is  fin- 
ish-.! ill  I'l.  II.  fig.  11. 

There  also  occurred  in  this  bank  a  modification  of  the  double  form  (PI.  II.  fig.  12; 
compare  with  PI.  II.  figs.  10,  11).  Again  this  form  appears  to  be  trebled  in  PI.  II.  fig. 
13.  A  unique  combination  of  the  double  form  with  the  single-type  form  is  seen  in  PI. 
III.  fig.  14.  Unfortunately  the  specimen  is  broken  in  its  weakest  part,  the  break  show- 
ing in  the  figure,  but  when  taken  from  its  bed  it  was  entire. 

It  is  interesting  to  note  in  this  connection  that  twenty-one  years  after  these  concre- 
tions were  collected  I  visited  the  place  again  and  took  from  the  same  bed  the  concretions 
fi-ured  in  I'l.  II.  fig.  12a  and  PI.  III.  fig.  14a  (compare  with  PI.  II.  fig.  12,  and  PL 
III.  fig.  14)  and  many  single  forms  like  PI.  I.  figs,  1,  6.  This  proves  that  in  one  bed,  at 
least,  the  typical  form  may  be  found  after  a  period  of  more  than  a  score  of  years.1 

Another  series  might  be  given,  one  of  which  is  shown  in  PI.  III.  fig.  15,  where  the 
only  markings  are  two  lines  running  along  the  outer  edge.  The  resemblance  of  this  con- 
cretion to  a  child's  worn-out  shoe  is  striking. 

Many  of  the  clay  beds  fail  to  yield  proportionately  so  many  perfected  forms  as  in 
the  cases  just  described.  PI.  III.  figs.  16-20  represent  concretions  from  a  bed  a  short 
distance  north  of  Sunderland  bridge  on  the  west  bank,  where  the  flattened  disc  marked 
by  a  deep  circle  (PI.  III.  fig.  20)  is  the  completed  form.  It  would  seem,  however,  that 
the  conditions  were  not  favorable  for  the  frequent  production  of  the  complete  form,  since 
tin;  majority  of  the  specimens  are  incomplete,  only  approximating  more  or  less  to  the  type 
form  as  seen  in  PI.  III.  figs.  16-19. 

In  the  process  of  growth  it  appears  that  the  original  circular  concretion  was  sur- 
rounded by  an  additional  broad  ring  (PL  III.  fig.  20).  In  PL  III.  fig.  16  two  discon- 
nected portions  of  this  ring  are  formed,  while  in  PL  III.  figs.  17-19  about  two-thirds  to 
nearly  the  whole  ring  is  finished.  A  slight  modification  of  this  type  is  seen  in  PL  IV. 
figs.  21-23,  where  that  portion  of  the  broad  ring  which  has  been  formed  is  marked  by  a 
deep  circular  impression  near  the  outer  edge.  In  PL  IV.  figs.  21,  22  only  about  one-third 
and  one-half  of  the  ring  is  formed,  while  in  PL  IV.  fig.  23  it  is  nearly  completed. 

1  I  am  indebted  to  Mr.  Arthur  E.  Jackson  of  Deerfield  for  aid  in  collecting  on  Saw  Mill  River  in  the  summer  of  1899. 


14  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 

It  sometimes  happens  that  a  clay  bed  produces  concretions  which  may  vary  individually 
within  certain  limits,  but  which  nevertheless  bear  a  general  resemblance  to  each  other. 
Thus  a  thin  layer  of  clay  just  south  of  the  west  end  of  Sunderland  bridge  yielded 
eighty-eight  concretions,  sixteen,  of  which  are  represented  in  PL  IV.  fig.  24.  There 
seemed  to  be  an  inexhaustible  supply  of  these  queer  little  images,  —  fishes,  birds,  ant- 
eaters,  elephants,  dogs,  babies'  feet,  —  as  we  found  them  abundantly  so  long  as  we  dug. 
While  they  vary  in  detail,  one  cannot  fail  to  see  a  marked  general  resemblance.  There 
are,  for  instance,  no  stout  clubs  (PL  I.  fig.  2),  or  spectacles  (PL  II.  figs.  10,  11),  or  disks 
(PL  III.  fig.  20)  among  them;  they  are  all  tiny  in  size  and  irregular  in  shape. 

Another  bed  on  the  east  bank  of  the  Connecticut,  a  short  distance  south  of  Rice's 
ferry,  yields  larger  irregular  concretions  which  are  bevelled  on  both  sides  to  a  sharp  edge. 
One  of  these  (PL  IV.  fig.  25)  was  taken  from  its  bed  while  in  the  process  of  forming,  and 
its  surfaces  are  roughened  by  the  clay  which  adheres  tightly  to  them.  These  concretions 
assume  various  shapes  like  animals  (PL  IV.  fig.  26),  boots  (PL  IV.  fig.  27),  etc.  But 
amidst  the  diversity  certain  characters  remain  constant, — the  flattened  form,  irregular 
outline,  and  the  sharpened  edges.  One  specimen  belonging  to  this  group  has,  in  addition 
to  these  characters,  a  perforation  (PL  IV.  fig.  28). 

The  animal-like  forms  represented  by  the  seal  (PL  I.  fig.  4)  or  the  goose  (PL  V. fig.  29) 
and  the  group  (PL  V.  fig.  30)  are  taken  from  another  bed.  These  have  plump  bodies, 
and  rounded  instead  of  sharpened  edges. 

I  have  already  given  several  examples  showing  a  preponderance  of  the  typical  forms 
in  their  respective  beds.  Many  more  examples  might  be  offered,  since  this  represents 
the  normal  condition. 

I  have  also  given  three  examples  proving  that  sometimes  a  close  general  resemblance 
is  preserved  when  the  specific  details  of  form  vary. 

Now  let  us  consider  a  case  where  the  completed  form  is  reached  only  by  one  out 
of  eleven  concretions  collected  from  the  same  clay  bed.  The  symmetry  and  beauty  of 
this  single  concretion  (PL  V.  fig.  31)  cannot  be  reproduced  on  paper,  though  no  pains 
have  been  spared  in  the  execution  of  the  drawing.  A  wreath  of  variously  colored  sand 
grains  and  tiny  pebbles  surrounds  the  central  portion,  and  for  this  reason  I  call  it  the 
wreath  concretion.  Eleven  other  concretions,  as  we  have  said,  were  found  with  this  one, 
but  some  of  them  are  far  removed  in  degree  of  perfection  from  the  typical  form. 
Notwithstanding  this  is  true,  one  need  only  glance  at  the  eleven  specimens,  ten  of  which 
are  represented  in  the  group  (PL  V.  fig.  32)  to  see  that  they  are  more  n'early  related  to 
the  almost  perfect  type-form  than  to  any  other  group.  The  conditions,  however,  for 
the  frequent  production  of  the  wreath  concretion  in  this  clay  bed  are  certainly  very 
unfavorable. 


OF    T1IK    ('((NNKCTICI  T    VAI.I.l  V  IT, 

All  tho  concretions  so  far  considered  have  been  comparatively  simple  forms.  By 
the>e  tir.M  we  are  better  aide  to  understand  the  complex  concretions,  such  as 
arc  illustrated  liv  PI.  \  1.  li^.  '.>'.'>.  The  process  of  growth  ot'  this  interesting  form  of 
concretion  is  shown  in  the  series  represented  by  PI.  VI.  figs.  34-47.  At  the  upper  left- 
hand  corner  is  the  original  form,  which  appears  to  bo  tho  first  stage  (PI.  VI.  fig.  34).  The 
slender,  gourd-shaped  concretions  (PI.  VI.  fig.  35)  and  the  stouter  form  (PI.  VI.  fig.  35') 
uro  similar  to  the  simple  concretions  we  have  already  been  considering.  The  two  parts 
of  which  PI.  VI.  figs.  35,  35'  are  made  up  become  modified  until  a  third  middle  portion 
is  formed  (PI.  VI.  figs.  36,  37,  38  and  36',  37',  38').  Examining  PI.  VI.  figs.  39-43,  it  is 
seen  that  PI.  VI.  figs.  35  and  36'  are  repeated  again  and  again  in  these  complex  concretions. 
There  are  numerous  variations;  the  part,  for  instance,  corresponding  to  the  body  of  the 
gourd  is  often  large  (PI.  VI.  figs.  40,  41,  43),  while  the  handle  may  be  small. 

The  process  of  growth  continuing,  new  little  gourds  like  those  in  PI.  VI.  figs.  35  and 
36'  are  added  on  the  edges  (PI.  VI.  figs.  42-44)  until  these  become  surrounded  and  are 
found  in  the  interior  of  the  concretion  (PI.  VI.  figs.  45,  46).  Oftentimes  the  largest 
specimens  of  this  kind,  like  PI.  VI.  fig.  47  (which  is  broken  at  both  ends  and  also  reduced 
about  one-half)  show  the  formation  less  clearly  than  those  of  medium  size  (PI.  VI.  fig. 
45.)  The  lines  are  often  so  obscure,  in  fact,  that  only  the  little  gourds  on  the  edges 
reveal  what  special  form  the  concretionary  process  tends  to  produce.  This  series  was 
selected  from  a  miscellaneous  collection  of  210  specimens,  of  which  128  showed  the  little 
gourds  distinctly  and  23  indistinctly,  while  in  22  concretions  they  could  not  be  made  out, 
owing  to  the  indefiniteness  of  the  lines.  The  remaining  37  concretions  were  wholly 
unlike  the  others,  and  doubtless  came  from  different  clay  beds. 

The  little  gourds  on  the  edges  of  the  concretions  are  fastened  tightly  to  the  main 
body,  as  proved  by  the  fact  that  although  the  collection  of  210  specimens  above  referred 
to  had  been  dumped  into  a  pail  without  any  special  care,  only  five  of  the  gourds  were 
found  broken  off  at  the  bottom  of  the  pail.  Amusing  caricatures  are  sometimes  found 
among  these  complex  concretions  (PL  VI.  fig.  48).  If  this  figure  is  turned  upside  down,  a 
second  head  appears.  Another  related  form,  although  not  so  much  flattened,  is  represented 
in  PI.  VI.  fig.  49,  the  head  of  which  is  seen  alone  in  PI.  VI.  fig.  50. 

Long  concretions  are  probably  made  by  the  coalescence  of  several  lying  in  a  straight 
line.  The  longest  concretion  in  our  collection  measures  twenty-two  inches,  and  this  is  not 
complete,  since  in  digging  it  from  the  clay  it  was  broken  and  the  end  could  not  be  found. 

Still  greater  irregularity  in  form  than  has  yet  been  described  is  shown  in  PI.  VII. 
figs.  51-55,  and  the  irregularity  is  increased  in  the  group  PI.  VII.  figs.  56-60,  where  it 
would  seem  as  if  the  concretions  were  built  up  by  a  method  of  daubing  or  plastering. 
These  concretions  are  from  Ryegate,  Vermont.  I  have  never  found  any  specimens  like 


16  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 

them.  Possibly,  if  a  larger  number  were  collected,  the  prevailing  tendency  might  be 
discovered,  and  order  brought  out  of  apparent  confusion. 

A  unique  concretion,  perhaps  belonging  to  the  above  group  but  differing  in  some 
ways  from  any  other  concretion  I  have  ever  seen,  is  now  in  the  Museum  of  the  Pocumtuck 
Valley  Memorial  Association  at  Deerfield.  I  am  indebted  to  the  president  of  this 
association,  Hon.  George  Sheldon,  for  the  opportunity  of  photographing  this  specimen 
and  other  instructive  concretions  in  the  society's  collection. 

The  locality  from  which  the  concretion  was  obtained  is  unknown,  but  for  various 
reasons  it  is  presumably  from  the  bank  of  the  Connecticut ;  its  reddish  tint  and  general 
aspect  being  similar  to  those  collected  farther  down  the  river  in  the  State  of  Connecticut. 
This  concretion  (PI.  VII.  fig.  61)  is  made  up  of  rounded  nodules  overlaid  in  part  by 
an  indefinite  number  of  clay  laminae.  These  laminae  tend  to  fill  up  the  hollows  and  to 
embrace  the  rounded  nodules.  Their  numerous  edges  are  exposed,  giving  an  excessively 
irregular  patchwork  appearance  to  the  concretion. 

The  reddish-colored  specimens  from  Windsor  and  Hartford  seem  to  fit  in  here,  if  we 
have  the  right  to  judge  from  the  limited  number  in  our  possession.  These  I  did  not 
collect  myself,  so  that  I  am  ignorant  of  the  exact  conditions  under  which  they  occur. 
They  illustrate  the  method  of  plastering  (PL  VII.  figs.  62-64),  although  oftentimes  there  is 
an  effort  to  preserve  symmetry.  The  two  specimens  (PI.  VII.  figs.  65,  66)  are  interesting 
in  this  connection.  On  the  convex  and  probably  the  upper  side  (PI.  VII.  figs.  65,  66) 
there  are  many  patches  of  clay,  while  on  the  flat  and  probably  the  lower  side  (PI.  VII. 
fig.  67,  flat  side  of  PL  VII.  fig.  65;  fig.  68,  flat  side  of"  PL  VII.  fig.  66)  the  pattern  is 
marked.  In  one  specimen  (PL  VII.  figs.  65,  67)  the  effort  seems  to  be  to  surround  the 
previously  formed  concretion  with  rings  of  clay,  while  in  the  other  specimen  (PL  VII.  figs. 
66,  68)  the  effort  is  to  build  out  horizontally  in  four  directions.  Greater  symmetry  is 
attained  in  PL  X.  fig.  69,  where  one  process  of  forming  new  rings  is  indicated. 

All  the  concretions  so  far  described  which  I  have  collected  have  been  taken  from  clay 
beds  on  the  banks  of  the  Connecticut.  It  must  not  be  supposed,  however,  that  these 
nodules  are  restricted  to  the  banks  of  the  river.  A  few  years  ago  Miss  C.  Alice  Baker 
called  my  attention  to  a  fine  exposure  on  one  of  the  rounded  hills  in  Great  River  or  East 
Deerfield,  which  is  reached  by  the  beautiful  wooded  road  running  from  Old  Deerfield 
Street,  over  East  Mountain  to  Rice's  ferry.  This  hill  is  a  quarter  of  a  mile  from  the 
Connecticut  River  and  about  seventy  feet  above  it.  The  southerly  exposure  (PL  VIII.,  from 
the  front ;  PL  IX.,  from  the  side)  shows  that  the  hill  is  largely  composed  of  clay  which 
has  been  baked  until  it  has  become  jointed.  This  clay  consists  mostly  of  dark  and  light 
colored  layers,  with  an  occasional  layer  of  sand.  The  dark  clay  has  been  used  for 
modeling,  while  the  light  is  too  friable  for  this  purpose.  The  latter  sometimes  has  a  gritty 


<>!••    TIIK    i  n.NNLiTICUT    VALLKY.  17 

feel,  indicating  the  presence  of  more  or  less  sand.  The  dark-colored  layers  are  harder 
than  tho  light,  so  that  they  resist  the  action  of  the  weather,  and  form  little  shelves  (see 
PI.  VIII.)  in  the  Bullies  or  miniature  canons  cut  in  the  face  of  the  hill  by  the  rivulets 
of  rain.  Notwithstanding  the  fact  that  this  hill  is  a  quarter  of  a  mile  from  the  Connecticut, 
concretions  are  found  in  it  in  considerable  numbers.  As  a  rule  they  are  small  in  size  and 
more  or  less  spherical  in  shape.  The  largest  sphere  I  have  ever  found  was  taken  from  this 
hill.  It  occurred  between  two  layers  and  not  in  a  layer,  and  is  represented  in  PI.  X.  fig.  70, 
nearly  natural  size.  Most  of  the  balls  are  much  smaller.  They  are  single  (PI.  X.  fig.  71) 
or  in  twos  (PI.  X.  fig.  72)  and  threes  (PI.  X.  fig.  73)  or  in  clusters  (PI.  X.  fig.  74).  Small, 
somewhat  flattened  forms  (PI.  X.  fig.  75)  occur,  but  they  are  rare,  and  are  probably 
confined  to  a  few  thin  layers  of  clay  that  do  not  contain  much  sand. 

Some  of  the  brooks  which  empty  into  the  Connecticut  offer  interesting  concretions. 
Canoe  Brook,  in  Dummerston,  Vermont,  after  leaving  the  hills  has  high  clay  banks 
which  slope  away  on  either  side.  These  banks  contain  similar  concretions,  those  from 
the  left  bank  being  represented  in  PI.  X.  figs.  76-78,  and  those  from  the  right  by  PI.  X. 
figs.  79-81.  They  are  extremely  irregular  in  outline  and  gritty  in  feel.  At  a  point  on 
this  brook  eighty  rods  from  its  mouth  wo  found  in  the  gravelly  bank  of  the  north  side  a 
large  number  of  the  concretions  which  the  rains  had  washed  from  the  high  clay  bank 
above.  Here  they  may  be  collected  by  hundreds.  Among  them  the  form  which  reminds 
one  of  the  cameo  brooch  (PI.  X.  fig.  82)  is  not  uncommon.  I  am  indebted  to  my  help- 
ful friend,  Giles  F.  Reed,  and  to  my  keen-eyed  six-year-old  collector,  John  E.  Walker, 
for  valuable  aid  while  exploring  this  part  of  Canoe  Brook.1 

1  Since  this  paper  was  prepared,  Miss  Emma  L.  Coleman,  of  Boston,  has  handed  me  several  dainty  specimens,  collected  by 
herself  many  years  ago  on  the  bank  of  the  Deerfield  River,  at  the  northerly  extremity  of  Pino  Hill,  in  Deerfield  North  Meadows. 
Four  years  ago  I  found  the  spot  entirely  overgrown  with  weeds  and  liru.-h. 

The  prevailing  form  of  the  concretions  is  almond-shaped,  one  side  being  plain,  and  the  other  marked  with  a  circling  line 
about  a  quarter  of  an  inch  from  the  edge.  The  texture  is  extremely  fine  and  homogeneous,  resembling  in  this  particular  the 
concretion  figured  on  1*1.  I.  fig.  5. 


18  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 


PART  II. 

HISTORICAL,  EXPERIMENTAL,  AND  THEORETICAL. 

[The  number  after  the  name  of  an  author  refers  to  a  corresponding  marginal  number  under  the  head 

of  Literature,  p.  39.] 


WE  have  been  dealing  so  far  with  concretions  as  they  are  found  in  situ,  or  as  they 
occur  when  washed  from  their  beds.  Observation  of  such  forms  and  of  the  con- 
ditions under  which  they  exist  has  suggested  and  helped  to  answer  the  three  important 
questions :  — 

First,  What  are  these  concretions  ? 

Secondly,  How  are  they  made  ? 

Thirdly,  What  determines  the  shape  of  a  concretion,  and  why  does  each  clay  bed 
produce  its  own  peculiar  form  ? 

The  first  question,  What  are  these  concretions  ?  has  been  answered  in  various  ways. 
In  1670  they  were  observed  when,  according  to  Hubbard  (37),  an  accident  fell  out  "  at  a 
place  called  Kennebunk  at  the  northeast  side  of  Wells  in  the  province  of  Maine,  not  far 
from  the  river  side,  a  piece  of  clay  ground  was  thrown  up  by  a  mineral  vapour  (as  is 
supposed)  over  the  top  of  high  oaks  that  grew  between  it  and  the  river.  The  said  ground 
so  thrown  up  fell  in  the  channel  of  the  river,  stopping  the  course  thereof,  and  leaving  an 
hole  forty  yards  square  in  the  place  whence  it  was  thrown,  in  which  were  found  thou- 
sands of  round  pellets  of  clay,  like  musket  bullets.  All  the  whole  town  of  Wells  are 
witnesses  of  the  truth  of  this  relation ;  and  many  others  have  seen  sundry  of  these  clay 
pellets  which  the  inhabitants  have  shewn  to  their  neighbours  of  other  towns." 

October  11,  the  same  year,  John  Winthrop  (78),  Governor  of  Connecticut,  writing 
to  Lord  Brereton  concerning  "the  strage  &  prodigious  wonder,"  says:  "The  relation 
wch  I  have  fro  credible  persons  concerning  the  manner  of  it  is  this :  That  the  hill  being 
about  8  rods  fro  Kennebunke  rivers  side,  on  the  west  side  of  the  river  about  4  miles  fro 
the  sea,  was  removed  over  the  drye  land  about  8  rods,  and  over  the  trees  also,  wch  grew 
betweene  the  hill  &  y*  river,  leaping  over  them  into  y*  river,  where  it  was  scene  placed, 
wth  the  upper  part  downward,  &  dammed  up  y*  river  for  a  tyme  till  the  water  did  worke 
its  selfe  a  passage  thorow  it.  The  length  of  the  hill  was  about  250  foote,  the  breadth  of 


OF  TIII:  o>v\T.tTi(MT  VALI.KV.  i:» 

it  about  80  foote,  the  depth  of  it  about  20  foote.  The  situation  of  the  hill  as  to  the 
length  of  it  was  iiorwest  it  southeast.  The  earth  of  it  is  a  blew  clay  wthout  stones, 
many  round  bullets  of  clay  were  wlhin  it  wrh  seem  to  be  of  the  same  clay  hardnod.  .  .  . 
I  had  from  them  [Major  William  Philips  and  Mr.  Herlakendiiio  Symonds]  some  few  of 
those  round  bullets,  A:  small  pieces  of  the  earth  in  other  forms,  wch  were  found  vpon  that 
now  vpper  part  w1'1'  was  l.rt'ore  the  lower,  or  inward  bowells  of  y"  hill,  as  also  a  small 
>liell  or  2  of  a  kind  of  shellfish  vstiell  in  many  places  of  the  sea,  but  how  they  should  be 
wthin  yl  hill  is  strage  to  cosider.  I  have  sent  all  y'  I  had  of  the"  amongst  other  things  to 
y*  lloyall  Society  for  their  repository." 

The  following  spring  ( Apr.  11,  1G71)  Governor  Winthrop  received  a  letter  from  Henry 
Oldenburg  to  this  effect :  "  I  soon  delivered  to  the  said  Society  [the  Royal  Society] 
their  parcel,  viz:  the  shellfish  (called  horsefoot)  the  Humming  Birds  nest,  with  the  two 
eggs  in  it,  being  yet  whole,  the  feathered  fly,  and  the  shells,  bullets  and  clays  taken  out 
of  the  overturned  hill,  for  all  which  that  noble  company  returns  you  their  hearty  thanks. 
.  .  .  Concerning  the  overturned  Hill,  it  is  wished  that  a  more  certain  and  punctual 
relation  might  be  procured  of  all  the  circumstances  of  the  accident."  Bourne  (8),  from 
whom  the  last  extract  is  taken,  goes  on  to  remark  that  "  No  intelligent  person  of  the 
present  ilav  can  hesitate  a  moment  as  to  the  explanation  of  this  strange  event.  The 
same  thing  has  occurred  several  times  within  the  last  fifty  years.  Oak  trees  then  stood 
all  along  the  banks  of  the  rivers,  and  this  wonder  was  one  of  those  avalanches  from  the 
banks  which  have  been  of  so  frequent  occurrence.  .  .  .  The  little  pellets,  which  were 
spoken  of  as  seen  after  the  slide,  were  rotted  up  by  the  avalanche  as  it  passed  over  the  solid 
ground  beneath."  (The  italics  are  mine.) 

In  1734  the  Journal  Book  of  the  Royal  Society,  Vol.  XV.,  contains  a  catalogue  of 
Natural  History  objects  found  in  New  England  by  John  Winthrop  (79),  in  which  is  this 
item :  "  Clay  generated  in  the  form  of  horseshoes  from  the  bottom  of  Connecticut 
River."  These  "horseshoes"  were  doubtless  concretions  (see  PI.  VII.  fig.  67). 

The  most  fully  illustrated  paper  on  concretions  that  I  have  seen  is  that  of  M.  Parrot 
(55;  see  also  73),  published  in  1840.  This  author  maintained  that  the  concretions  were 
organic  in  their  origin,  being  probably  the  petrifactions  of  the  soft  bodies  of  some  kind  of 
mollusk. 

Another  view  is  reported  by  Professor  Edward  Hitchcock  (33)  in  1841,  who  speaks 
of  receiving  a  concretion  from  an  able  English  geologist,  labeled  "  Kimmeridge  Coal 
Money  (use  and  age  unknown,)  found  abundantly  in  the  Kimmeridge  Clay,  Dorset  Coast. 
—  Supposed  turned  in  a  lathe  and  anciently  used  as  money." 

There  are  honest  folk  at  the  present  time  who  think  that  many  of  these  peculiar 
forms  are  fossil  animals  which  lived  in  some  prehistoric  age.  As  recently  as  1889  a  con- 


20  CONCEETIONS   FEOM   THE   CHAMPLAIN   CLAYS 

cretion  (figured  in  PL  X.  fig.  83)  was  sent  to  the  Boston  Society  of  Natural  History 
with  an  explanatory  letter,  a  portion  of  which  ran  as  follows :  "  The  accompanying 
letter  will  tell  why  I  now  address  you.  Herewith  please  find  a  specimen  of  petrified 
organic  matter  in  the  form  of  a  turtle ;  some  say  toad,  which  I  desire  to  have  classified. 
It  must  have  passed  through  three  terrible  ordeals,  clay  bed,  brick  machine,  and  fire. 
I  will  give  you  the  history  of  the  find  in  brief.  In  Bridgeport,  Conn.,  in  the  autumn 
of  1874  curiosity  called  me  upon  a  pile  of  brick  which  some  laborers  were  moving 
on  the  wharf,  and  as  I  made  a  casual  glance  towards  the  men,  one  of  them  dropped  a 
brick  which  broke  in  two  equal  parts,  and  being  very  near  I  noticed  something  pro- 
truding from  one  of  the  halves  of  the  brick,  when  I  jumped  down,  picked  up  the  half, 
and  to  my  astonishment  found  it  was  the  accompanying  specimen,  one  half  out  of  his 
shell,  the  brick.  I  soon  dislodged  him  from  his  situation,  and  gathered  up  the  other  half 
of  the  brick,  and  took  the  two  parts  to  the  store  of  a  friend,  where  I  left  them,  as  they 
were  cumbersome,  and  at  that  moment  I  thought  them  of  no  consequence,  but  since  I 
have  experienced  sorrows  and  regrets  for  not  preserving  the  two  pieces  of  brick  which 
would  demonstrate  beyond  all  question ;  but,  however,  the  story  is  a  fact  all  the  same.  I 
have  always  held  the  specimen  valuable  as  a  curiosity  among  some  other  little  matters, 
and  seeing  a  paragraph  in  the  Boston  Record  which  said  some  one  had  bought  a  speci- 
men of  a  petrified  turtle,  —  and  the  only  one  known,  —  for  which  he  paid  $40.00,  I 
brushed  the  dust  from  my  specimen  in  order  to  get  its  value  and  classification  in  its 
once  animated  form.  Awaiting  your  decision,  I  am,"  etc. 

These  views  and  others  mentioned  by  M.  Virlet  (73)  and  Gratacap  (24)  have  influenced 
the  popular  mind.  It  is  indeed  surprising  to  find  how  general  is  the  belief,  outside  of  the 
strictly  scientific  circle,  that  these  concretions,  "claystones"  or  "clay-dogs"  as  they  are 
called,  are  made  of  clay  which  has  been  worn  into  shape  by  running  water. 

A  short  and  direct  road  to  the  solution  of  this  part  of  the  problem  is  found  in  chemical 
analysis.  The  following  results  I  obtained  from  a  series  of  analyses  made  to  ascertain 
approximately  the  percentage  of  carbonate  of  lime  or  calcium  carbonate  in  the  concretions 
and  in  the  clay  immediately  surrounding  them. 

Concretion,  Deerfield,  west  end  Whitmore't  ferry.—  Calcium  carbonate  (CaCO8)  In  concretion,  42  per  cent 
Calcium  carbonate  (CaC03)  in  clay  surrounding  concretion,  2  to  3  per  cent. 

Concretion,  Deerfield,  south  of  Sunderland  bridge,  west  bank.  —  CaCO3  in  concretion,  43  per  cent 
CaCO3  in  surrounding  clay,  2-3  per  cent. 

Concretion,  Brattleboro.  —  CaCO3,  42  per  cent. 

Concretion,  Hartford.  —  CaC03,  47  per  cent. 

Professor  Hitchcock  (33)  gives  four  analyses,  thus:  42.1,  48.4,  49.9,  and  56.6  per 
cent  of  calcium  carbonate.  The  last  is  an  analysis  of  a  concretion  from  Hadley,  and 
the  amount  of  the  carbonate  is  large. 


• 

OF   THE  CONNECTICUT   VALLEY.  21 


Professor  C.  B.  Adams  (1)  publishes  a  number  of  analyses  of  concretions  from 
different  towns  in  Vermont  in  which  the  percentage  of  carbonate  of  lime  runs  as 
follows:  claystone,  Dummerston  51.08;  Addison  45.09  ;  Alburgli  53.17  ;  Pittsford  42.88 ; 
Derby  49j;i;:  Shell. urn.-  .V2.58  ;  Norwich  44.84. 

T.  Storry  Hunt  (38)  got  the  following  results  from  analyses  of  concretions  in  the 
same  State.  We  give  only  the  percentage  of  carbonate  of  lime,  with  one  exception. 
Kyegate  40.2;  Bethel  40.9;  Pittsford  44.3;  Rutland  44.4;  Norwich  40.8;  Sharon 
1.'..3;  Ryegate  35.8.  The  last  is  an  analysis  of  a  concretion  which  contained  64.2  per 
cent  of  coarse  sand  and  clay. 

These  figures  prove  that  the  quantity  of  calcium  carbonate  in  these  concretions, 
though  not  definite,  does  not  greatly  vary.  We  may  say  that  about  half  a  concretion 
is  made  of  this  substance,  while  the  remainder,  as  shown  by  the  analyses  on  p.  29,  is 
largely  either  clay  or  sand  (silicate  of  aluminum  or  silica). 

In  answer  to  the  first  question,  What  are  these  concretions  1  it  may  therefore  be  said 
that  the  concretions  with  which  we  are  dealing  are  usually  hardened  masses  composed 
largely  of  calcium  carbonate  and  clay  and  having  a  more  or  less  definite  form.  The 
essential  difference  between  the  concretion  and  the  clay  immediately  surrounding  it,  as 
shown  by  the  analyses  on  p.  20,  is  the  small  percentage  of  calcium  carbonate  in  the 
latter  compared  with  that  in  the  former.  The  concretion  really  robs  the  clay  around  it 
of  its  lime. 

In  order  to  answer  the  second  question,  How  are  these  concretions  made  ?  we  must 
consider  briefly  the  theory  of  concretionary  structure  which  is  now  almost  universally 
accepted  by  naturalists. 

According  to  this  theory  the  particles  or  molecules  of  certain  substances,  calcium 
carbonate  for  instance,  when  held  in  solution  tend  to  flock  together.  This  process  of 
flocking  together  is  called  segregation.  When,  for  one  reason  or  another,  a  tiny  particle 
of  calcium  carbonate  has  been  precipitated  in  a  solid  form,  this  particle  acts  as  a  centre  of 
attraction,  and  draws  more  calcium  carbonate  to  itself.  If  the  process  were  not  hindered 
in  any  way,  as  for  instance  by  the  presence  of  a  foreign  substance,  the  resultant  form 
would  be  a  crystal  of  calcium  carbonate.  But  if  a  foreign  substance,  such  as  clay,  be 
present  which  the  particles  of  calcium  carbonate  are  not  vigorous  enough  to  push  one  side, 
then  the  calcium  carbonate  is  deposited  between  and  around  the  clay  particles,  and  the 
resultant  form  is  a  concretion  made  chiefly  of  calcium  carbonate  and  clay.  This  is  a 
general  statement  in  regard  to  the  concretionary  process.  We  naturally  seek  to  know 
more  than  this  gives  us  of  the  history  of  a  concretion.  Whence  came  the  Champlain 
clays,  the  homes  of  the  "  claystones"  T  Whence  came  the  carbonate  of  lime  or  limestone 
disseminated  through  these  clays?  What  caused  the  carbonate  of  lime  to  dissolve  and 


22  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 

afterward  to  be  deposited  in  solid  form  !  What  is  the  subtle  force  that  binds  the  particles 
of  an  inorganic  substance  together  ? 

While  some  of  the  details  of  this  history  are  as  yet  unknown,  others  are  well  established. 
The  Champlain  clays  originated  by  the  decomposition  of  old  feldspathic  rocks.  A  vast 
amount  of  this  decomposed  clayey  material  together  with  sand  and  gravel  was  brought 
down  from  higher  latitudes  by  glaciers.  The  warm  climate  which  followed  the  arctic  winter 
of  the  glacial  period  caused  the  melting  of  the  ice,  and  large  areas  of  land  were  in 
consequence  covered  by  water.  In  these  quiet  seas  the  Champlain  clays  were  deposited. 
Subsequently  the  region  rose,  the  deposits  became,  in  part,  dry  land,  and  rivers  cut  their 
way  downward  through  the  clay  strata  to  the  depth  of  many  feet. 

Analyses  of  these  drift  clays  deposited  during  the  Champlain  period  prove  that  they 
are  not  made  of  pure  kaolin,  but  that  they  consist  of  various  substances.  According  to 
Blatchley  (7),  the  drift  clays  of  Indiana  show  the  presence  of  as  high  as  40  per  cent  of 
calcareous  material.  This  is  due,  says  this  writer,  to  the  grinding  up  and  mixing  with 
the  clays  of  much  of  the  surface  limestones  over  which  the  glaciers  passed.  These  eroded 
limestones  and  the  clays  were  ground  into  an  impalpable  powder  or  "rock  flour."  [On 
this  subject  see  also  Crosby  (11)  and  Shaler  (64).] 

Cooke  (10),  in  his  analyses  of  the  Tertiary  marls  and  clays  of  the  Maltese  islands, 
found  the  quantitative  variations  of  the  several  components  of  the  rock  to  be  considerable, 
as  shown  by  the  following  table :  — 

Carbonate  of  lime,  2  to  67  per  cent. 

Sulphate  of  lime,  4  to  30  per  cent. 

Carbonate  of  magnesia,  faint  traces  to  distinct  traces. 

Phosphate  of  lime,  traces  to  2  per  cent. 

Alumina,  25  to  58  per  cent. 

Oxides  of  iron,  4  to  10  per  cent. 

Residue  insoluble  in  dilute  hydrochloric  acid,  3  to  10  per  cent. 

[See  also  analyses  by  Murray  (51).] 

It  is  evident  from  the  analyses  already  given  that  most  clay  contains  more  or  less 
calcium  carbonate  in  a  solid  form ;  how  does  this  solid  carbonate  pass  into  a  liquid  state  ? 

It  is  well  known  that  all  rocks,  not  excepting  the  so-called  "  impervious  clay,"  allow 
the  passage  of  percolating  waters.  The  joints  and  irregular  cracks  in  the  clay  are  the 
highways  for  these  ground  waters  from  which  they  spread  throughout  the  denser  strata. 
In  passing  downward  from  the  surface  they  come  in  contact  with  more  or  less  decom- 
posing organic  matter  which  is  giving  off  carbon  dioxide,  commonly  called  carbonic  acid 
gas ;  the  latter  is  taken  up  by  the  percolating  waters,  which  thereby  are  able  to  dissolve 
the  calcium  carbonate.  Julien  (41)  has  pointed  out  that  not  only  carbon  dioxide  but 


OF  THE  CONNECTILTT    VAI.I.I  V  23 

probably  tlic  humus  acids  —  a  complex  gmup  <>t  the  products  of  organic  decay  —  play 
an  important  part  in  the  solution  of  the  calcium  carl>on;ite  ami  in  the  origin  of  tho  con- 
cretions, as  is  stated  more  fully  farther  on  .see  p.  24). 

It  is  easy  to  see  that  the  ground  waters  must  be  subject  to  constant  changes.  They 
are  influenced  by  seasons  of  drought  and  rainfall,  by  the  quantity  of  carbon  dioxide  or 
other  solvents  present,  by  the  amount  of  calcium  carbonate  in  the  clay  matrix,  and 
doubtless  by  other  causes.  Some  of  the  changes  would  tend  to  bring  about  the  solidifi- 
cation or  crystallization  of  tiny  particles  of  calcium  carbonate,  or,  it  may  be,  a  saturated 
solution  of  this  substance  would  deposit  some  of  its  calcium  carbonate  on  already  existing 
particles. 

Questions  arise  concerning  tho  exact  process  which  are  at  present  unsettled.  Nichols 
(53)  has  shown  that  it  is  difficult  to  see  why  periods  of  solution  and  deposition  of  calcium 
carbonate  corresponding  to  the  changes  in  the  character  of  the  solvent  waters  "should 
cause  tho  segregation  into  concretions  of  the  previously  scattered  particles,  for  it  is  to  be 
expected  that  deposition  of  material  would  take  place  upon  the  separate  particles  in  the 
same  ratio  as  solution,  so  that  their  relative  sizes  would  be  preserved,  even  though  each 
increase  or  diminish  in  weight.  At  first  thought  it  may  seem  that  some  particles  may 
be  more  favorably  situated  than  others,  but  here  also  those  most  favorably  situated  to 
receive  material  during  periods  of  deposition  will  be  most  favorably  situated  to  lose 
material  during  periods  of  solution."  The  writer  continues :  "If  alternate  solution  and 
deposition  by  the  solvent  waters  were  alone  sufficient  to  cause  segregation  and  the  for- 
mation  of  concretions,  then  the  calcium  carbonate  in  all  calcareous  clays  and  shales  should 
be  in  the  form  of  concretions.  There  is,  however,  an  abundance  of  occurrences  of  cal- 
careous clay  and  shale  where  the  calcite  yet  remains  disseminated." 

An  explanation  for  these  phenomena  Nichols  finds  in  the  modern  theories  of  satu- 
rated solutions,  which  he  maintains  should  be  applied  to  this  problem  in  tho  way  that 
chemists  have  already  applied  it  to  the  growth  of  crystals.  "There  are  two  conditions 
which,  in  the  light  of  these  theories,"  he  says,  "  appear  favorable  to  the  formation  of  con- 
cretions. These  are:  (1)  The  presence  of  aragonite  with  the  disseminated  calcite  of 
the  clay  beds ;  (2)  the  presence  of  the  unstable  humus  acids." 

Carbonate  of  lime  occurs  in  clay  beds  in  two  forms,  as  aragonite  and  calcite.  Ara- 
gonite is  more  soluble  than  calcite  and  therefore  is  dissolved  first.  It  is  well  known  to 
chemists  that  a  saturated  solution  of  aragonite  deposits  calcite,  not  aragonite,  and  it 
follows  that  this  calcite  would  be  attracted  towards  and  be  deposited  on  the  already 
existing  solid  particles  of  calcite  scattered  through  the  clay  bed. 

According  to  this  theory  concretions  owe  their  origin  to  the  greater  solubility  of 
aragonite  and  the  transformation  of  this  aragonite  into  calcite.  The  second  condition 


24  CONCRETIONS   FROM   THE  CHAMPLAIN   CLAYS 

favorable  for  the  production  of  concretions,  as  pointed  out  by  Nichols,  is  the  presence  of 
the  humus  acids  in  the  percolating  waters.  Certain  modifications  of  this  complex  group 
of  acids  have  a  strong  solvent  action  upon  calcium  carbonate,  while  other  modifications 
render  it  nearly  insoluble.  The  acids  are  so  unstable  that  they  are  constantly  under- 
going changes.  When  they  lose  part  of  their  solvent  power  they  become  supersaturated 
with  calcium  carbonate  and  deposit  it  upon  the  existing  solid  calcite  particles,  thus  caus- 
ing the  concretions  to  grow. 

The  question,  What  is  the  subtle  force  that  draws  the  particles  of  an  inorganic  sub- 
stance together?  cannot  be  answered  satisfactorily.  Call  this  force  by  what  name  we  may, 
—  chemical  attraction,  affinity,  electrical  agency, — it  surely  challenges  our  profoundest 
thought.  Its  origin  unknown,  its  modus  operand!  imperfectly  understood,  it  neverthe- 
less is  found  operative  throughout  both  inorganic  and  organic  nature ;  for  as  we  rise  in 
the  ascending  scale  of  life,  we  find  this  power  exhibited  in  varying  degrees  in  the  dif- 
ferent groups  of  living  organisms,  until  finally  we  reach  human  life,  the  most  complex 
manifestation  of  organic  nature,  where  its  most  perfect  and  most  potent  expression  is  in 
the  life  of  the  family  and  the  larger  life  of  the  race. 

It  has  been  generally  believed  that  every  concretion  has  a  centre  of  attraction  or 
nucleus  of  appreciable  size,  like  a  shell,  pebble,  etc.  Such  a  specimen  with  a  good-sized 
pebble  at  its  heart  is  seen  in  PI.  X.  fig.  84.  Weathering  has  caused  the  concretion  to 
split  in  two,  exposing  the  pebble  in  one  half  and  the  corresponding  concavity  in  the 
other  (PI.  X.  fig.  85).  Dr.  Hall  (26)  speaks  of  concretions  having  for  a  nucleus  a  bit  of 
iron  pyrite,  a  shell,  or  a  crystal  of  carbonate  of  lime. 

With  the  aid  of  Professor  W.  O.  Crosby,  a  concretion  from  the  mouth  of  Saw  Mill 
River  was  sawed  in  two  vertically  and  polished  (PL  X.  fig.  86).  Lines  of  stratification 
were  distinctly  seen,  but  with  this  exception  the  mass  looked  perfectly  homogeneous. 
There  was  not  the  slightest  evidence  of  a  nucleus  or  of  concentric  structure ;  the  latter, 
however,  developed  gradually  after  long  exposure  to  the  air.  One  of  the  halves  was 
sawed  in  two  again,  giving  a  sharp  angle  which  proved  the  extreme  fineness  of  the 
material.  A  quarter  was  etched  in  hydrochloric  acid,  and  while  this  brought  out  a  con- 
centric structure,  it  did  not  reveal  a  nucleus.  Little  spherical  cavities  were  seen,  as  if 
the  tendency  to  concretionary  structure  was  so  great  that  the  concreting  material  was  not 
satisfied  with  forming  one  large  concretion,  and  so  made  smaller  ones  within  the  larger. 
I  also  dissolved  a  concretion  in  hydrochloric  acid  and  examined  the  insoluble  residue 
upon  a  filter.  It  was  impalpably  fine  clay,  and  no  foreign  particle  of  any  appreciable 
size  was  present.  Professor  Hitchcock  (33)  says  on  this  subject,  "  In  no  case  in  Massa- 
chusetts have  I  seen  an  organic  relic  as  a  nucleus."  In  1859  Mr.  Charles  Stodder  (66) 
exhibited  at  a  meeting  of  the  Boston  Society  of  Natural  History  two  concretions  cut  open, 


UK   T11K    CoNNKiTKTT    VALI.KV.  25 

one  showing  a  nucleus  less  than  one  sixteenth  of  an  inch  in  diameter,  while  the  other  was 
without  a  visible  nucleus.  In  the  light  of  these  facts  it  seems  safe  to  say  that  many 
concretions  have  no  nucleus  of  any  appreciable  size,  though  they  may  have  one  in  the 
form  of  such  a  minute  crystal  of  calcium  carbonate  that  it  cannot  be  detected  by  the  eye. 
Professor  B.  K.  Emerson  (19),  after  stating  that  so  far  as  all  the  Connecticut  Valley  con- 
cretions are  concerned,  the  li  initiating  cause  entirely  eludes  our  observation,"  points 
out  that  in  exactly  similar  concretions  from  other  localities  a  nucleus  exists  in  the  form 
of  organic  matter.  This  nucleus  in  some  cases  is  hermetically  sealed  and  decom- 
position is  thereby  arrested;  in  other  cases  it  is  probably  "wholly  dissipated  into  liquid 
or  gaseous  compounds  before  the  concretionary  process  is  far  advanced."  "  Such  a 
nucleus,  now  wholly  vanished,"  according  to  Professor  Emerson,  "  may  have  determined 
the  beginning  of  the  concretions  we  are  discussing;"  and  he  finds  proof  for  this  theory 
in  the  fact  that  a  distinct  residue  of  inflammable  organic  matter  was  found  in  the  anal- 
yses of  these  concretions  made  by  Professor  Hitchcock.  (See  Hyams'  analysis,  p.  30.) 

We  have  spoken  of  the  lines  of  stratification  running  through  the  concretion,  and 
these  have  been  seen  in  the  vertical  section  of  the  Saw  Mill  River  specimen  (PI.  X.  fig.  86). 
These  stratification  lines  often  run  with  unbroken  continuity  through  the  concretion 
and  its  surrounding  clay.  This  is  shown  in  PI.  X.  fig.  87 ;  x  is  the  line  of  stratification 
which  represents  the  thin  lamina  of  reddish  clay  (PI.  X.  fig.  87,  x)  that  is  rendered  more 
conspicuous  than  the  other  laminae  by  its  red  color.  This  fact  that  the  layers  are 
continuous  proves  that  the  concretion  was  formed  subsequently  to  the  deposition  of  the 
clay,  and  that  the  concretionary  process  went  on  so  quietly  that  the  layers  of  stratification 
were  not  disturbed.  When  concretions  have  been  exposed  to  the  action  of  the  carbon 
dioxide  in  the  atmosphere,  or,  in  other  words,  have  "  weathered,"  the  edges  of  the  laminae 
are  often  brought  out  clearly  (PI.  X.  figs.  88,  89),  and  sometimes  the  specimen  breaks 
into  separate  layers.  PL  X.  fig.  90  is  an  unusually  fine  illustration  of  such  weathering, 
showing  how  very  evenly  the  upper  layer  has  split  off  from  the  lower  layers. 

Sometimes  the  concretionary  process  ceases  while  in  the  very  act  of  making  a 
concretion,  and  then,  after  a  longer  or  shorter  period,  begins  again.  In  such  a  case 
the  resultant  form  when  weathered  and  broken  shows  the  different  stages  of  growth.  This 
is  seen  in  PL  XI.  fig.  91,  where  about  one  half  of  the  upper  layer  has  been  taken  off,  thus 
exposing  a  portion  of  the  central  circular  concretion  that  was  first  formed.  In  PL  XL  fig.  92 
nearly  half  of  the  same  specimen  has  been  broken  away,  revealing  still  more  of  the  first- 
formed  concretion.  PL  XI.  fig.  93  is  a  specimen  that  has  weathered  in  a  different  way.  The 
first-formed  concretion,  represented  by  the  central  portion  of  PL  XI.  fig.  93,  has  separated 
from  the  later-formed  portions  (PL  XI.  fig.  94),  and  has  split  into  layers.  Thus  the  central 
part  of  PL  XI.  fig.  93,  when  removed  and  turned  over,  is  shown  in  PL  XI.  fig.  96.  The 


26  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 

remaining  central  portion  removed  is  represented  in  PI.  XI.  fig.  95.  These  two  figures 
(PI.  XI.  figs.  95,  96)  have  peculiar  markings  which  remind  one  of  the  impressions  of  fossil 
medusae  that  Walcott  (74)  has  recently  discovered  among  the  Cambrian  rocks.  I  have  not 
a  sufficient  number  of  these  specimens  for  comparison  and  study  to  offer  any  explanation 
of  their  interesting  markings. 

Sometimes  the  different  stages  of  growth  are  marked  off  from  each  other  by  a  decided 
difference  in  color  (PI.  XI.  fig.  97),  or  by  a  difference  in  texture  ;  when  these  specimens 
weather,  they  often  show  the  different  stages  finely,  as  seen  in  PI.  XI.  fig.  98,  which 
represent  PI.  XI.  fig.  97  split  in  two. 

We  now  come  to  the  third  question,  What  determines  the  shape  of  a  concretion,  and 
why  does  each  clay  bed  have  its  own  peculiar  form  ?  We  will  first  consider  a  case 
where  the  conditions  are  most  favorable  for  the  production  of  concretions.  We  need,  in 
such  a  case,  a  bed  of  sand,  not  clay,  through  which  water  percolates  containing  calcium 
carbonate  in  solution.  As  already  stated,  a  particle  of  this  substance,  deposited  in  solid 
form,  acts  as  a  nucleus  which  draws  to  itself  other  particles  of  calcium  carbonate.  We 
have  already  pointed  out  (see  ante,  p.  21)  that  if  this  process  continued  without  interference 
the  result  would  be  a  crystal  of  calcium  carbonate  with  even  surfaces  and  sharp  angles. 
It  happens,  however,  with  the  sand  as  with  the  clay,  that  its  grains  are  not  forced  out  of 
the  way,  but  remain  in  place,  and  are  surrounded  by  the  carbonate,  so  that  instead  of  a 
crystal,  a  concretion  results  composed  of  carbonate  of  lime  and  sand. 

The  bed  of  sand  is  porous,  and  is  usually  made  up  of  thick  layers,  so  that  the  water 
holding  calcium  carbonate  in  solution  can  percolate  freely  in  every  direction.  The 
concretion,  consequently,  grows  on  all  sides,  so  that  the  resultant  form  is  more  or  less 
spherical.  This  is  the  normal  shape  of  concretions  taken  from  sand  beds.  A  fine 
illustration  of  such  a  spherical  form  is  given  by  Worthen  in  Hall  and  Whitney's  Geology 
of  Iowa  (27  and  81). 

The  conditions  in  clay  beds,  on  the  other  hand,  are  very  different  from  those  of  sand 
beds,  and  the  concretions  are  therefore  obliged  to  adapt  themselves  to  circumstances. 
The  clay  is  a  compact  mass  through  which,  as  compared  with  sand,  water  percolates  with 
difficulty.  The  clay  beds  are  made  up  of  many  layers  (PI.  XI.  fig.  99)  which  spread 
out  horizontally,  but  which  are,  as  a  rule,  much  thinner  vertically  than  the  layers  in  a  bed 
of  sand.  The  water  holding  calcium  carbonate  in  solution  finds  difficulty,  as  already 
stated,  in  percolating  through  the  exceedingly  fine  material,  but  it  makes  its  way  laterally 
in  one  layer,  or  between  two  layers,  with  greater  ease  than  vertically  through  several 
layers.  As  a  result  the  concretion  spreads  out  laterally,  as  seen  in  the  embedded  specimens 
(PI.  XI.  fig.  100;  PI.  XII.  fig.  101),  and  also  in  PI.  XII.  figs.  102, 103,  where  the  top  layer 
has  been  taken  off. 


"I-1    Till     CONNB    III'I    I     YAM. I  V  27 

I'nlessthe  concretions  are  of  small  si/e.  like  those  from  the  clav  hill  at  (Jreat  Ri\cr 
(PI.  X.  figs.  71-71 1.  they  are  almost  invarialily  flattened.  This  is  slum  n  hy  nearly  all 
the  concretions  in  our  collection. 

The  concretionary  tendency  is  so  strong  that  it  operates  even  when  the  conditions 
are  so  adverse  that  only  crude,  shapeless  masses  result  such  as  is  seen  in  I'l.  XII.  iig.  104. 
Although  there  are  -<-\  mil  centres  of  attraction,  the.  whole  mass  is  most  imperfect 
Another  specimen  (PI.  XII.  fig.  lO.'il  >eems  to  be  in  an  unfinished  condition,  the  lower 
nnsymmetrical  portion  being  nearly  as  hard  as  the  upper  more  symmetrical  part.  In 
PI.  X 1 1.  fig.  106,  there  are  two  partly  finished  concretions  with  a  shapeless  mass  of  hardened 
clay  between.  Sometimes  the  angularity  is  increased  by  the  gravel  stones  that  are 
partly  or  wholly  surrounded  by  the  concreting  material  (PI.  XII.  figs.  107-109),  which 
in  some  cases  overlap  the  sharp  edges  of  the  rock  fragment  (PI.  XII.  fig.  109). 

We  have  already  shown  that  the  comparative  thinness  of  the  clay  layers  produces 
the  flattened  form  of  concretion.  We  had  what  was  apparently  a  mass  of  clay  composed 
of  three  distinct  layers.  When  the  specimen  was  broken  in  two,  as  shown  in  PI.  XIII. 
fii:s.  110,  111,  there  was  revealed  a  concretion  (PI.  XIII.  fig.  Ill)  in  the  process  of  making. 
The  concavity  into  which  the  concretion  fitted  is  seen  in  PI.  XIII.  fig.  110.  The  middle 
layer  containing  the  concretion  was  darker  colored  than  the  layer  above  or  below,  so  that 
its  vertical  thickness  could  be  easily  measured. 

This  specimen  is  especially  interesting  as  showing  that  some  concretions,  at  least,  are 
in  a  plastic  state  for  a  longer  or  shorter  time  before  hardening.  The  concretion  could  be 
broken  easily,  being  in  this  respect  totally  different  from  any  other  concretion  I  have 
collected.  Analyses  of  this  concretion  and  of  the  light  and  dark-colored  layers  of  clay 
are  given  on  p.  34. 

In  our  collection  the  concretions  from  Brattleboro  are  among  the  thinnest  (PI.  XIII. 
fig.  112,  vertical  view;  fig.  113,  horizontal  view),  and  some  of  those  from  Hartford  are 
the  thickest  (PI.  XIII.  figs.  114,  115).  The  "baby's  head"  (PI.  XIII.  fig.  116)  which 
was  found  in  a  Deerfield  clay  bed  comes  nearer  the  Hartford  specimens  in  point  of 
thickness  than  any  of  the  other  concretions  collected. 

All  the  Brattleboro  concretions  that  I  have  seen  are  irregular  in  outline  and  are 
bevelled  to  a  rounded  edge.  They  are  not  marked  by  lines  of  ornamentation  of  any  kind. 
Their  homogeneous  texture,  slippery  feel,  and  bluish  color  show  that  they  are  remarkably 
free  from  sand  grains  or  other  foreign  matter. 

Another  unique  form  of  a  flat  concretion  differing  from  any  other  in  our  collection 
is  represented  in  PI.  XIV.  figs.  117,  118.  They  are  taken  from  a  clay  bed  on  the  east 
bank  of  the  Connecticut,  nearly  opposite  the  village  of  South  Vernon.  These  concretions 
are  of  nearly  the  same  thickness  throughout,  which  is  unusual.  The  edge  is  not  bevelled, 


28  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 

as  in  most  cases,  but  is  at  right  angles  to  the  horizontal  surface  (PI.  XIV.  fig.  118),  like 
the  tire  of  a  wagon  wheel  or  the  milled  edge  of  a  silver  dollar.  One  of  these  concretions 
(PI.  XIV.  fig.  118)  is  interesting  for  another  reason.  One  side,  which  is  that  shown  in  the 
figure,  is  marked  by  distinct  concentric  lines  showing  that  the  concretion  grew  by 
the  addition  of  successive  rings  in  the  same  plane. 

Another  important  determining  cause  of  the  shape  of  a  concretion  is  the  varying 
amount  of  dissolved  calcium  carbonate  in  the  different  layers  of  clay.  If,  for  instance, 
one  layer  is  rich  in  this  substance,  and  the  layer  above  or  below  is  poor  in  it,  then  one  part 
of  the  concretion  may  be  smaller  than  the  other,  as  is  the  case  with  the  Saw  Mill  River 
concretions  (PI.  I.  figs.  1,  6,  8  ;  PI.  II.  figs.  10, 11).  Thus  it  is  seen  that  the  structure  of  clay 
masses  has  much  to  do  with  the  shapes  of  concretions ;  nevertheless,  it  does  not  adequately 
explain  why  one  mass  should  yield  watch-shaped  specimens,  another  spectacles,  another 
animal  forms,  and  so  on. 

It  was  with  a  desire  to  know  more  of  the  individual  concretions  of  the  separate  beds 
in  order  to  make  comparisons  between  the  different  types,  that  I  had  several  series  of 
analyses  made,  which  are  given  on  p.  29. 

This  work  has  been  done  with  painstaking  care,  and  according  to  the  most  modern 
methods  of  chemical  research,  by  Isabel  Finzi  Hyams,  private  assistant  in  the  Massachusetts 
Institute  of  Technology,  and  for  ten  years  assistant  chemist  in  the  State  Board  of  Health 
Laboratory  for  water  analysis. 

These  analyses  were  made  with  a  view  of  ascertaining :  first,  whether  similar  forms 
taken  from  the  same  clay  bed  were  alike  or  unlike  in  composition.  Secondly,  whether 
symmetrical  and  unsymmetrical  forms  had  the  same  or  different  composition.  Thirdly, 
whether  there  was  a  definite  composition  for  a  definite  form,  or  whether  the  shape  was 
wholly  independent  of  the  constituents.  Fourthly,  whether  chemical  analysis  would 
throw  additional  light  on  the  determining  cause  or  causes  of  the  different  and  peculiar 
shapes  of  concretions.  I  chose  for  these  analyses  four  of  the  symmetrical  specimens 
from  the  Saw  Mill  River  bed,  two  of  which  were  first  photographed  (PL  I.  fig.  6,  and  PI. 
II.  fig.  10);  three  irregular,  unsymmetrical  "east  bank"  forms,  like  those  figured  in  PI. 
IV.  fig.  25  ;  and  three  "  river  bottom  "  specimens  (PI.  VI.  fig.  33).  These  series  represented 
the  concretions  taken  from  river  clay  beds ;  in  addition  to  these  I  selected  one  series 
of  three  specimens  of  the  spherical  concretions  (PI.  X.  figs.  71-74)  from  the  inland  hill. 
The  analyses  in  the  first  three  series  were  made  in  duplicate  to  insure  greater  accuracy  in 
the  results. 


OF   THK   CONNKCTICI  T    VAI.I.KV. 


29 


The  concretions  ground  in  each  case  sufficiently  fine  to  pass  through  bolting  cloth 
were  digested  with  hydrochloric  acid  [HC1  (1:  1),  that  is,  one  part  acid  to  one  part  water]. 
The  insoluble  residue  was  brought  into  solution  by  fusion  with  sodium  carbonate  (NajC()3). 
The  amount  of  this  residue  is  given  on  the  extreme  left  of  the  table. 


After  Treatment  of 

Residue 

HCI. 

•Re«. 

HCI. 

*  Hon. 

HCI. 

•Res. 

HCI. 

*Kes. 

HCI. 

•Ret. 

HCI. 

•  lie,. 

>  "" 

with  HCI. 

SiO, 

SiOa 

Fe,0. 

Ke.,0. 

AI.O, 

Al,0, 

CaO. 

CaO. 

MgO. 

Mt!<>. 

MnO. 

MnO. 

CO, 

1  S.  M.  11.    ... 
1  B.  M.  R  

•J  S.  M.  R. 

"  S    \[    U 

N..t  IVt 

40.47 

8&M 

39.10 

.15 
.24 

.21 
.18 

27.  ss 
27.97 

88.21 

L'S.U'l 

3.53 

3.04 

2.74 

.43 
.73 

.56 

4.39 
4.69 

4.49 
4.54 

7.38 

25.01 
24.59 

25.22 

.71 
.69 

.88 

1.05 
1.12 

1.76 

0.0 
0.5 

.34 

4.58 
4.56 

4.40 

(UN 

0.05 

0.00 

21.76 
21.60 

21.23 
21  H 

US   M.  K.,  fused") 
direct,  i.e.,  with-  [ 
out   dissolving  | 
in  HCI.               J 

::  s    M.  R  
:,  >.  \I.  K  

38.82 
38.70 

28. 

.15 
.13 

10 

29.11 
28.94 

3. 

3.71 
3.66 

39 

.65 
.81 

15. 

4.41 
3.88 

38 

6.51 
6.93 

26. 
26.83 

79 

.91 

•-'.•J.' 

1. 
1.98 

73 

0.00 
0.00 

4. 
5.25 

32 

0.00 
0.00 

21.60 
21.45 

4  S.  M.  R  

3844 

.11 

28.77 

3.55 

.46 

4.45 

6.23 

1.83 

2.01 

0.00 

0.00 

21.18 

4  S.  M.  K  
1  K.  B  

3S.39 
25.91 

.16 
.079 

L'S.91 

19.05 

3.61 
5.76 

.57 
.44 

3.59 
5.00 

693 
5.19 

24.18 
29.13 

3.24 
2.34 

1.93 

0.00 

5.11 
5.44 

0.00 
0.00 

21.27 
25.51 

1  K.  H.  .      .  . 

27.04 

.063 

19.06 

5.66 

.47 

5.05 

5.03 

2.63 

2.25 

0.00 

5  44 

0.00 

25  66 

2  K.  H.  .  .  . 

2681 

0.00 

18.74 

5.40 

.49 

5.80 

6.79 

27.87 

0.92 

2.09 

0.31 

5.38 

0.00 

23.69 

2  E.  B  

26.83 

0.00 

18.64 

5.59 

5.91 

27.45 

0.97 

1.55 

0.23 

5.36 

0.00 

23.84 

3  K.  B.   . 

26.95 

.18 

19.10 

5.78 

.38 

5.74 

5.45 

27.98 

0.85 

1.96 

0.43 

5.22 

0.00 

24.50 

8  E.  B  
1  R.  B  

26.96 
38.04 

.19 

.1" 

18.99 
27.73 

5.63 
3.61 

.41 
.50 

6.01 
4.40 

5.29 
7.54 

28.36 
26.44 

0.95 
1.20 

1.89 
1.78 

0.43 
.16 

5.41 
.32 

0.00 
0.00 

24.57 
22.60 

1  K.  H.  .  . 

38.14 

.35 

27.30 

3  •_'(( 

1.02 

6.24 

24.88 

.83 

1.59 

.47 

.25 

0.13 

22.52 

2  R.  B.  .  . 

M.M 

.29 

26.40 

3.  |:i 

.64 

4.98 

8.93 

24.84 

1.04 

1.39 

0.00 

.22 

000 

20.50 

2  R.  B  

38.16 

.17 

27.96 

3.7-> 

.50 

4.56 

7.33 

26.51 

.99 

1.85 

0.22 

.16 

0.00 

20.43 

3  R.  B.  . 

M.M 

.11 

27.97 

3.41 

.58 

4.54 

7.66 

27.63 

.91 

1.72 

0.31 

.13 

0.00 

22.13 

3  R,  B  

:',s.  1C 

.23 

27.68 

3.34 

.64 

4.59 

7.66 

26.59 

1.89 

1.77 

0.35 

.11 

0.00 

22.23 

\l',    H  Spheres 

40.53 

30.36 

.086 

3.26 

1.20 

6.96 

7.62 

28.63 

1.19 

0.69 

0  20 

19.87 

2  G.  R.  Spheres    . 

42.09 

31.07 

0.00 

4.92 

1.08 

5.25 

7.16 

26.81 

1.31 

3  87 

0.38 

19.71 
19.90 

3  G.  R.  Spheres    . 

47.30 

35.10 

0.00 

2.35 

1.34 

6.48 

7.24 

28.75 

1.74 

3.63 

0  27 

19.82 
20.18 

1G.  R.,  Light  Clay 

2  G.  R.,  Dark  Clay 

3  G.  R.,  Enclosed  ? 
Concretion          ^ 

78.98 
70.11 
57.31 

59.12 
51.70 
42.76 

.18 
.20 
.17 

4.74 
8.02 
12.65 

0.5 
0.79 
1.01 

6.77 
10.35 
15.95 

12.82 
10.08 
9.54 

1.02 
0.97 
1.18 

1.23 
1.89 

1.85 
0.51 
2.09 

0.62 
0.76 
0.00 

1.97 
.94 
1.10 

Trace 
0.00 
0.00 

19.95 

1.47 
1.34 

.30 
.30 

.20 
.18 

•Residue  from  HCI  solution  fused  with  Na,CO,. 


In  both  the   hydrochloric   acid   solution  and   the  insoluble  residue   the  following 
substances  were  determined  (excepting  in  the  cases  indicated  by  dots):  silica  (Si02);  iron 


30 


CONCRETIONS   FROM   THE   CHAMPLAIN    CLAYS 


oxide  (Fe203);  aluminum  oxide  or  alumina  (A1203) ;  calcium  oxide  or  lime  (CaO); 
magnesium  oxide  or  magnesia  (MgOj ;  and  manganese  oxide  (MnO). 

It  seemed  better  to  give  the  results  in  the  form  of  oxides  rather  than  carbonates  and 
silicates,  since  one  cannot  be  absolutely  sure  that  all  the  carbon  dioxide  is  combined  with 
the  calcium  to  form  calcium  carbonate,  as  some  of  it  may  be  united  with  the  iron  or  the 
manganese.  It  is  true  we  can  calculate  how  much  a  certain  per  cent  of  calcium  oxide  will 
require  of  carbon  dioxide  to  make  the  compound  calcium  carbonate,  but  this  is  an  indirect 
and  not  absolutely  certain  method.  Neither  can  it  be  told  with  certainty  how  much 
silica  is  combined  with  aluminum  to  form  the  silicate  of  aluminum,  since  it  is  probable 
that  the  silicates  are  mixed. 

The  carbon  dioxide,  expelled  by  boiling  hydrochloric  acid,  was  determined  in  duplicate 
in  all  the  samples.  The  per  cent  of  alkalies  (Na2O  and  K20)  was  determined  in  two 
samples  by  fusion  with  calcium  carbonate,  according  to  the  J.  Lawrence  Smith  method, 
and  2  to  3  per  cent  was  found.  The  determination  in  the  other  samples  seemed 
unnecessary. 

The  concretions  were  also  tested  to  see  if  any  of  the  silica  was  in  the  form  of 
hydrated  silicic  acid,  but  it  was  not ;  a  part  was  sand,  and  a  part  was  combined  with  the 
bases  of  the  clay. 

The  trace  of  water  present  in  the  concretions  was  not  determined.  One  concretion 
was  tested  for  titanic  acid,  but  yielded  none. 

The  organic  matter  was  determined  by  the  Kjeldahl  process,  and  calculated  as 
ammonia  (NH3)  in  one  of  the  specimens  from  the  east  bank  and  in  one  Saw  Mill  River 
concretion.  Only  a  trace  was  found,  the  former  yielding  one  hundredth  of  one  per  cent, 
and  the  latter  about  half  as  much.  It  may  be  that  the  organic  matter  is  present  only 
in  a  carbonaceous  form,  but  the  indications  are  that  it  exists,  if  at  all,  in  a  very  small 
amount. 

The  weights  of  the  concretions  analyzed  were  as  follows :  — 


SAW  MILL  RIVER  CONCRETIONS. 

1.  104.3  grains. 

2.  92.5      " 

3.  103.5      " 

4.  200         " 

EAST  BANK  CONCRETIONS. 

1.  28.5  grains. 

2.  20.2      " 

3.  18.3      " 


RIVER  BOTTOM  CONCRETIONS. 

1.  36.2  grains. 

2.  48.1      " 

3.  17.3      " 

INLAND  HILL  CONCRETIONS. 

1.  1.9  grains. 

2.  1.8      " 

3.  1.2      " 


OF  TIIK   CONNECTICUT    VAI.I.KY. 


31 


It  is  clear  that  the  per  rent  of  each  oxide  in  the  hydrochloric  acid  solution,  and  in 
the  fusion  which  was  made  from  the  residue  from  the  hydrochloric  acid  solution,  when 
added  together,  ^ives  the  whole  amount  of  such  oxide  in  the  concretion.  When  this  is 
done  the  following  results  are  obtained  with  the  four  Saw  Mill  River  concretions:  — 


ASMI-I-    i>K     F.illi    Cos.  -KKTIOKS    FROM    SAW    MlLL    1\IV1K 


No.  1 

Silica 28.03 

Iron  oxide    ...  3.96 

Alumina     ....  8.88 

Lime -J.'i.Ti' 

Magnesia  ....  1.05 

.M.-mir.-int'so  oxi.lc  l.(!7 

Carbon  dioxide  .  21.7i; 

No.  2 

Silica 28.42 

In. I,  oxide     .   .   .  3.30 

Alumina     ....  12.07 

Lime 26.10 

Magnesia  ....  2.10 

Manganese  oxide  4.40 

Carbon  dioxide  .  21.23 


No.  1 

Silica i 

Iron  oxide   .  .   .  3.77 

*  Alumina      ....  

Lime 25.28 

Magnesia  ....  1.17 

Manikin. 'so  o\i<lc  4.61 

Carbon  dioxide  .  21.60 

No.  2 

Silica 28.10 

Iron  oxide    .  .   .  3.39 

Alumina    ...  15.38 

Lime 26.79 

Magnesia  .  •  .  .  1.73 

Manganese  oxide  4.32 

Carbon  dioxide  .  21. 


No.  3 

Silica 29.26 

Iron  oxide     .   .  .  4.36 

Alumina     ....  10.92 

Lime 27.71 

Magnesia  ....  1.98 

Manganese  oxide  5.25 

Carbon  dioxide  .  21.60 

No.  4 

Silica 28.88 

Iron  oxide    .  .  .  4.01 

Alumina    ....  10.68 

Lime 

Magnesia  ....  2.01 

Manganese  oxide    

Carbon  dioxide  .  21.27 


No.  3 

Silica 29.07 

Iron  oxide  .  .  .  4.27 
Alumina  ....  10.81 

Lime 

Magnesia  ....    

Manganese  oxide    

Carbon  dioxide  .  21.45 

No.  4 

Silica 29.10 

Iron  oxide  ...  4.18 
Alumina  ....  10.52 

Lime 27.42 

Magnesia  .  .  .  1.93 
Manganese  oxide  5.11 
Carbon  dioxide  .  21.27 


*  The  line  indicates  that  the  oxide  wag  not  determined. 


Comparing  the  average  percentage  obtained  by  these  analyses,  we  find,  without  giving 
the  hundredths,  that  the  per  cent  of  carbon  dioxide  is  constant  in  the  four  specimens,  and 
that  there  is  21  per  cent  of  this  substance  present. 

The  insoluble  residue  after  treating  with  hydrochloric  acid  is  38  per  cent  in  two  out 
of  the  four  concretions,  and  the  variation  is  2  per  cent  only.  We  find  28  per  cent  of  silica 
in  three  specimens  out  of  the  four,  and  the  variation  is  only  1  per  cent  There  is  nearly  2 
per  cent  of  magnesium  oxide  in  three  specimens,  and  the  variation  is  less  than  1  per  cent. 
Of  manganese  oxide  two  concretions  yield  4  per  cent  and  two  5  per  cent ;  of  iron  oxide 
two  3  per  cent  and  two  4  per  cent ;  the  variation,  however,  in  each  of  these  oxides  is  less 
than  1  per  cent.  The  calcium  carbonate  varies  only  2  per  cent.  There  is  a  greater 
difference  in  the  oxide  of  aluminum,  but  while  the  variation  in  the  four  specimens  is  from 
8  to  13  per  cent,  two  of  them  yield  10  per  cent. 

Judging  from  these  results,  we  may  say  that  while  the  proportions  are  not  fixed  and 
constant,  still  these  four  concretions  from  one  clay  bed  are  remarkably  uniform  in  their 
composition.  Let  us  see  if  the  same  holds  good  in  the  case  of  the  specimens  from  one 
of  the  clay  beds  on  the  east  bank. 


32 


CONCRETIONS  FROM   THE  CHAMPLAIN   CLAYS 


ANALYSES  OF  THREE  CONCRETIONS  FROM  A  BED  ON  THE  EAST  BANK  OF  THE  CONNECTICUT, 

NEAR  RICE'S  FERRY. 


No.  1 

Silica 19.129 

Iron  oxide    ...  6.20 

Alumina     ....  10.19 

Lime 31.47 

Magnesia  ....    

Manganese  oxide  5.44 

Carbon  dioxide  .  25.51 


No.  1 

Silica 19.123 

Iron  oxide  ...  6.13 
Alumina  ....  10.08 

Lime      

Magnesia  ....  2.25 
Manganese  oxide  5.44 
Carbon  dioxide  .  25. 

No.  3 

Silica 19.28 

Iron  oxide  ...  6.16 
Alumina  .  .  .  .  11.19 

Lime 28.83 

Magnesia  ....  2.39 
Manganese  oxide  5.22 
Carbon  dioxide  .  24.50 


No.  2 

Silica 18.74 

Iron  oxide  ...  5.89 
Alumina  ....  12.59 

Lime 28.79 

Magnesia  ....  2.40 
Manganese  oxide  5.38 
Carbon  dioxide  .  23.69 

No.  3 

Silica 19.18 

Iron  oxide    ...  6.04 

Alumina     ....  11.30 

Lime 29.31 

Magnesia   ....  2.32 

Manganese  oxide  5.41 

Carbon  dioxide  .  24.57 


No.  2 

Silica 18.64 

Iron  oxide    .  .   .    

Alumina     ....    

Lime 28.42 

Magnesia  ....  1.78 
Manganese  oxide  5.36 
Carbon  dioxide  .  23;84 


In  this  series  the  variation  of  carbon  dioxide  is  1.5  per  cent.  Insoluble  residue 
26  per  cent  in  the  three  concretions,  variation  less  than  1  per  cent.  Silica,  19  per  cent  in 
two  out  of  three  specimens,  variation  less  than  1  per  cent.  Manganese  oxide  constant  — 
5  per  cent.  Iron  oxide  6  per  cent  in  two  specimens,  variation  less  than  1  per  cent. 
Magnesium  oxide  2  per  cent,  variation  less  than  1  per  cent.  Calcium  oxide,  variation  3 
per  cent,  and  aluminum  oxide,  variation  2  per  cent. 

Here,  again,  the  composition  of  the  concretions  from  the  same  bed  is  pretty  uniform, 
although  there  is  a  greater  variation  in  the  carbon  dioxide  and  the  calcium  oxide  than  in 
the  first  series.  If  now  we  compare  the  analyses  of  the  symmetrical  forms  represented 
by  the  first  series  (p.  31)  with  those  of  the  unsymmetrical  forms  (given  above),  we  find 
marked  differences.  There  is  a  larger  amount  of  silica  in  the  former  than  in  the  latter,  the 
average  excess  being  9.62  per  cent;  a  smaller  per  cent  of  carbon  dioxide,  the  average 
being  3.12  per  cent,  also  of  calcium  oxide,  2.94  per  cent. 

We  will  next  consider  the  "river  bottom"  specimens  which  have  a  character  of 
their  own,  being  a  colony,  so  to  speak,  of  symmetrical  single  forms.  These  are  called 
"  river  bottom  "  specimens  because  they  are  dug  from  the  clay  of  the  river  bottom  and 
not  from  the  river  bank. 


OF  THE  CONNKCTICUT    VAI.I.l  V. 


33 


&JULYHH  OK  TIIKKK  liivKK  BOTTOM  CONCRETIONS. 


No.  1 

Silica 17.98 

Iron  oxide     ...     4.11 

Alumina     .   .   .    .  11. '.M 

I.iiiu- L'T.f.l 

Magnesia  ....     1.94 

::mese  oxide  4.32 

Carbon  dioxide   .  22.60 


No.  1 

Silica 27.65 

Iron  oxide    .  .   .  I.'-'L' 

Alumina     ....    

Linn- 2.V71 

M:i£ni'si:i   ....  2.1  MI 

Manganese  oxide     4.38 
Carbon  dioxide  .   -'-. 

No.  3 

Silica 28.08 

Iron  oxide     .  .  .  3.99 

Alumina     ....  12.20 

Lime 28.54 

Magnesia   ....  2.03 

Manganese  oxide  4.13 


No.  2 

Silica 26.69 

Iron  oxide  .  .  .  4.07 
Alumina  ....  13.91 

Lime 25.88 

Magnesia  ....  I..T.I 
.Manganese  oxide  I.-J 
Carbon  dioxide  .  20. 

No.  3 

Silica 27.91 

Iron  oxide    ...  3.98 

Alumina     ....  12.25 

Lime 28.48 

Magnesia  ....  2.12 

Manganese  oxide  4.11 


No.  2 

Silica 28.13 

Iron  oxide    .   .  .  I  JJ 

Alumina    .   .   .  .  1  !.>'.' 

Lime 27. ..o 

Magnesia  ....  2.07 

Manganese  oxide  4.16 

Carbon  dioxide  .  20. 


Carbon  dioxide   .  22.13        Carbon  dioxide  .  22.23 


It  is  interesting  to  note  that  the  composition  of  these  concretions  is  much  nearer  that 
of  the  symmetrical  specimens  from  Saw  Mill  River  than  that  of  the  unsymmetrical  forms. 
(Compare  analyses  on  pp.  31,  32,  33.)  Stated  in  a  general  way,  the  results  run  thus:  — 


Saw  Mill 
River 

....         38 

East  Bank 
26 

Kiver  Bottom 
38 

Silica     

.   .    .    .         28 

19 

27,  28 

Iron  oxide    

3,  4 

6 

4 

.  .  .  .        10 

10-12 

11-13 

.   .  .  .  25-27 

28-31 

25-28 

Magnesia 

1,2 

2 

1,2 

Manganese  oxide      4,  5 

Carbon  dioxide 21 


23-25 


20-22 


ANALYSES  OF  THREE  SPECIMENS  OF  SPHERES  FROM  THE  ISLAND  HILL. 


No.  1 

Silica 31.22 

Iron  oxide 4.46 

Alumina 14.54 

Lime 29.82 

Magnesia 

Manganese  oxide 89 

Carbon  dioxide 19.71 


No.  2 

Silica 31.07 

Iron  oxide 6.' 

Alumina 12.41 

Lime 28.12 

Magnesia 

Manganese  oxide    ....     4.25 
Carbon  dioxide  .  19.82 


No.  3 

Silica 35.10 

Iron  oxide 3.69 

Alumina 13.72 

Lime 80.49 

Magnesia 

Manganese  oxide    ....     3.90 
Carbon  dioxide 19.95 


By  examining  these   analyses    of  the  spherical  concretions  from   the   inland  hill. 
we  find   that   the   composition   of  the   three   specimens   is  similar,  but  that  it   differs 


34 


CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 


essentially  from  the  composition  of  the  other  concretions  we  have  been  considering. 
There  is  a  much  larger  insoluble  residue  (from  40  to  47  per  cent),  and  the  amount  of  silica 
is  greater  (from  31  to  35  per  cent).  For  some  reason  the  manganese  oxide,  which  is  very 
constant  in  the  other  concretions,  varies  here  from  .89  to  4.25  per  cent.  In  these  specimens 
there  is  the  smallest  amount  of  carbon  dioxide  (19  per  cent)  so  far  found.  We  have  seen 
from  the  foregoing  analyses  that  concretions  from  the  same  bed  are  similar  in  composition, 
and  that  each  bed,  while  it  is  consistent  with  itself,  differs  from  other  beds.  This  difference, 
however,  is  not  sufficiently  great  to  thi-ow  much  additional  light  on  the  causes  of  the 
marked  differences  in  the  shapes  of  the  concretions.  Perhaps  more  could  be  ascertained, 
however,  if  a  larger  number  of  series  of  analyses  were  made. 

Pieces  of  clay  were  cut  from  the  strata  of  the  inland  hill  some  distance  from  those 
in  which  the  spherical  concretions  were  found.  On  breaking  one  piece  in  two  some 
months  later,  to  our  surprise  a  concretion  was  revealed  (see  PI.  XIII.  fig.  111).  As  stated 
on  p.  27,  the  specimen  of  clay  consisted  of  three  layers.  One  was  light  in  color  and 
extremely  friable,  while  the  layer  in  which  the  concretion  was  embedded  was  dark-colored 
and  could  be  iised  for  moulding.  An  analysis  of  both  layers  and  of  the  enclosed 
concretion  gave  the  following  results :  — 


LIGHT  CLAY  LAYER. 

Silica 59.30 

Iron  oxide 5.24 

Alumina 19.59 

Lime 2.25 

Magnesia 2.47 

Manganese  oxide    ....  1.97 

Carbon  dioxide 1.34 


DARK  CLAY  LAYER. 

Silica 51.90 

Iron  oxide 8.81 

Alumina 20.43 

Lime 97 

Magnesia 1.27 

Manganese  oxide 94 

Carbon  dioxide 30 


ENCLOSED  CONCRETION. 

Silica 42.93 

Iron  oxide 13.66 

Alumina 25.49 

Lime 3.07 

Magnesia 2.09 

Manganese  oxide    ....     1.10 
Carbon  dioxide 18 


The  light  layer  consists  principally  of  silica  and  alumina  with  a  very  small  amount 
of  calcium  oxide  and  carbon  dioxide.  The  dark  layer  contains  more  iron  and  aluminum 
oxide,  and  not  even  1  per  cent  of  either  calcium  oxide  or  carbon  dioxide.  Undoubtedly 
water  and  organic  matter  aid  the  iron  in  making  the  clay  dark-colored  and  plastic. 

The  concretion  was  darker  in  color  than  most  concretions,  and  this  was  doubtless 
owing  to  the  iron,  since  there  was  present  more  than  three  times  the  quantity  found  in 
the  Saw  Mill  River  concretions.  Although  there  is  more  calcium  oxide  in  the  concretion 
than  in  the  dark  layer,  there  is  only  3  per  cent,  and  less  than  1  per  cent  of  carbon 
dioxide. 

Under  these  conditions  it  is  surprising  that  the  concretionary  form  should  be  so  well 
marked  unless  the  iron  was  the  active  agent  in  the  work.  If  the  manganese  aids 
materially  in  hardening  the  concretion,  as  is  probable,  then  the  small  quantity  of  it  in 
this  concretion  may  be  one  cause  of  its  soft  condition. 


OF  Till-    CONNECTICUT   v.\ I.I.I  35 

A  secondary  modification  of  the  clay  layers,  produced  doubtless  by  mechanical 
|>rr»mv.  has  caused  certain  peculiar  modifications  in  the  shapes  of  concretions.  There 
is  a  specimen  of  clay  in  the  geological  museum  of  Amherst  College  in  which  the  original 
horizontal  layers  have  lin-n  pushed  into  folds.  Although  so  far  as  I  know  there  is  no 
record  of  concretions  having  been  observed  in  the  crests  of  these  distorted  folds, 
nevertheless.  In-lit  concretions  from  unknown  localities  are  found  in  collections.  Professor 
Kmerson(19)  figures  a  specimen,  and  the  original  shows  the  folded  layers  even  better  than 
the  figure.  V\.  XIV.  figs.  119,  120,  are  views  of  a  bent  concretion  in  our  collection.  The 
upper  surface  is  seen  in  PI.  XIV.  fig.  119,  and  the  side  view  in  PI.  XIV.  fig.  120,  which 
gives  the  angle  of  the  fold.  Crude  specimens  apparently  warped,  so  to  speak,  from  a 
horizontal  plane  are  represented  in  PL  XIV.  figs.  121,  122.  The  latter  was  mounted  on 
glass  and  unintentionally  placed  in  such  a  way  as  to  cast  a  reflection  of  itself,  thereby 
showing  more  clearly  the  scooped  out,  twisted  condition  of  the  concretion.  Another 
specimen  telling  of  distorted  and  crumpled  layers  is  seen  in  PI.  XIV.  fig.  123,  which  in 
the  original  has  the  semblance  of  an  old  crushed  hat. 


36  CONCKETIOXS   FROM  THE  CHAMPLAIN  CLAYS 


GENERAL  SUMMARY. 


PART  I. 

nPHE  concretions  described  in  this  paper  are  from  the  following  localities :  The  banks 
-*-  of  the  Connecticut  from  Dummerston,  Vermont,  to  Deerfield,  Massachusetts,  inclu- 
sive ;  the  banks  of  the  Saw  Mill  and  Deerfield  rivers  and  of  Canoe  Brook,  tributaries  of 
the  Connecticut ;  an  inland  hill  in  the  town  of  Deerfield ;  Windsor  and  Hartford,  Con- 
necticut; and  Ryegate,  Vermont. 

The  collection  of  concretions  numbers  fourteen  hundred  specimens. 

The  only  time  for  collecting  river  bank  specimens  successfully  is  in  seasons  of 
drought  when  the  streams  are  low. 

The  equipment  for  collecting  is  a  good  boat,  a  shovel,  trowel,  stout  carving-knife, 
rubber  boots,  boxes,  and  wrapping  paper. 

In  searching,  the  course  should  be  up  stream,  that  the  concretions  lying  along  shore 
may  not  be  hidden  by  the  turbid  water. 

The  concretions  from  each  clay  bed  should  be  kept  separate. 

Each  bed  has  a  typical  form,  which  is  more  or  less  perfect  as  the  conditions  are 
favorable  or  adverse. 

A  watch-shaped  and  a  club-like  concretion  have  not  been  found  embedded  together,  or 
a  botryoidal  mass  and  an  animal  form.  These  are  typical  concretions  of  as  many  sepa- 
rate beds.  One  bed  yielded  twenty-four  similar  concretions ;  another  bed  forty-eight. 

The  typical  single  form  may  be  doubled  or  trebled,  and  illustrations  are  given  which 
tend  to  prove  that  the  double  form  is  due  to  the  union  of  two  single  forms. 

Single  and  double  concretions  like  those  collected  in  1878  from  the  north  bank  of 
Saw  Mill  River,  were  taken  from  the  same  clay  bed  after  an  interval  of  twenty-one  years. 

Under  unfavorable  conditions  the  typical  form  is  not  perfected  so  often,  although 
there  always  seems  to  be  an  effort  in  that  direction. 

Three  series  of  specimens  are  given  which  prove  that  a  close  general  resemblance 
may  be  preserved  when  the  specific  details  of  form  vary. 

Simple  forms  give  rise  to  complex  forms  by  coalescence,  as  shown  by  the  union  of 
many  gourd-shaped  concretions.  The  little  gourds  are  fastened  tightly  to  the  main  body 
of  the  concretion,  as  was  proved  by  the  striking  example  on  p.  15. 


ill--  Till-:  OONHECTICl  T   VAI.I.I  37 

The.  longest  concretion  in  this  collection,  measuring  twenty-two  inches,  is  probably 
formed  by  the  coalescence  of  several  concretions  lying  in  a  straight  line. 

As  a  rule  one  side  of  a  concretion  is  flatter  than  the  other  and  without  ornamentation. 
An  exception  to  tills  rule  is  illustrated  by  two  specimens  from  Hartford. 

Concretions  are  found  not  only  in  river  banks,  but.  also  in  inland  hills;  the  latter  are 
illustrated  by  the  spherical  concretions  from  the  rounded  hill  in  East  Deerfield. 

PART  II. 

In  1670  the  question  was  asked;  What  are  these  shapely  pieces  of  hardened  clayt 
A  brief  historical  sketch  offers  some  of  the  answers  that  have  been  given. 

Various  chemical  analyses  for  the  determination  of  calcium  carbonate  and  foreign 
matter  have  led  to  the  conclusion  that  about  half  the  concretion  is  carbonate  of  lime,  and 
the  remainder  largely  clay  and  sand. 

The  essential  difference  between  the  concretion  and  the  surrounding  clay,  as  shown 
by  analyses,  is  the  small  percentage  of  calcium  carbonate  in  the  latter  as  compared  with 
that  of  the  former. 

In  order  to  answer  the  question,  How  are  these  concretions  made  I  the  theory  of 
concretionary  structure  as  generally  held  by  naturalists  to-day  is  given,  and  the  views 
of  Blatchley  on  drift  clays  and  "  rock  flour,"  of  Julien  on  the  action  of  the  humus  acids, 
and  of  Nichols  on  the  part  played  by  aragonite  are  considered.  The  subject  of  the 
presence  or  absence  of  a  nucleus  is  discussed,  and  it  is  shown  that  the  sections  and 
weathered  specimens  described  do  not  reveal  a  nucleus  of  appreciable  size,  excepting  in 
one  case  where  a  pebble  is  found  at  the  centre.  Etching  with  hydrochloric  acid  brings 
out  a  concentric  structure,  and  also  shows  that  the  tendency  to  concretionary  structure  is 
so  great  that  the  concreting  material  makes  small  concretions  within  the  larger  one. 

Stratification  lines  are  shown  to  run  not  only  through  the  concretions,  but  also  with 
unbroken  continuity  through  the  concretions  and  the  surrounding  clay. 

Illustrations  are  given  which  tend  to  prove  that  the  concretionary  process  may  stop 
while  in  the  act  of  making  a  concretion,  and  afterward  begin  again  ;  when  such  specimens 
weather,  the  different  stages  fall  apart  and  are  often  distinguished  by  marked  differences 
in  color. 

The  shape  of  a  concretion  is  partly  determined  by  the  structure  and  composition 
of  the  matrix  which  holds  it,  and  by  the  amount  of  carbon  dioxide  and  other  organic 
acids  present. 

A  single  specimen  described  was  found  in  a  plastic  condition. 


38  CONCRETIONS   FROM   THE    CHAMPLAIN    CLAYS 

Four  series  of  analyses  were  made  of  concretions  from  four  different  beds,  as  follows: 
Four  symmetrical  specimens  from  the  Saw  Mill  River  bed. 
Three  unsymmetrical  specimens  from  near  Rice's  ferry. 
Three  compound  concretions  from  the  river  bottom. 
Three  spherical  concretions  from  the  inland  hill. 

The  analyses  showed :  — 

First :  similar  forms  from  the  same  bed  are  essentially  alike  in  composition. 

Secondly :  the  composition  of  symmetrical  forms  differs  from  that  of  the  unsym- 
metrical ones;  this  difference,  however,  is  not  sufficiently  great  to  explain  the  marked 
differences  in  shape. 

Thirdly :  the  composition  of  the  compound  concretions,  made  up  of  symmetrical 
single  forms,  is  more  nearly  like  that  of  the  symmetrical  single  forms  than  that  of  the 
unsymmetrical  specimens. 

Fourthly  :  the  composition  of  the  spherical  concretions  from  the  inland  hill,  and  that 
of  the  surrounding  clay,  differs  from  the  river  bank  specimens  in  the  presence  of  a  larger 
amount  of  silica ;  this  fact  doubtless  explains  their  spherical  form. 

Analyses  of  the  plastic  concretion  showed  an  extremely  small  amount  of  lime  and 
carbon  dioxide,  but  a  large  amount,  comparatively  speaking,  of  iron. 

Secondary  modifications  in  shape  are  produced  by  mechanical  pressure,  as  shown  by 
bent  concretions. 


OF  THE  CONNECTICUT  VALLEY.  39 


LITERATURE. 


The  bibliography  on  the  special   subject  of   this  paper  includes,  perhaps,  the  names  of   not  more  than  half  a  dozen   author*,  but  the 
literature  on  the  general  »ul>  ,  concretionary  structure,  and  drift  clays  which  I  bare  examined  ii  given  below  for  the  benefit 

f  iliii  branch  of  geological  science. 

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!  Annual  Report  on  the  Geology  of  the  State  of  Vermont,  1846 ;  Concretions,  pp.  111-118;  Clay  Deposit!,  etc,  pp. 
140-142;  Analysis,  p.  255. 

2.  Andra,  Prof. 

I'lpwpliiitic  Concretions  from  Waldlx'irkelheim,  Verh.  nat.  Vcr.  preuss.  Rheinl.,  Jahrg.  XXXIII.,  Sits.  1876,  p.  191. 

3.  Andrews.  Thos. 

!•  ( 'iiriuns  Concretion  Balls  Derived  from  a  Colliery  Mineral  Water,  Chemical  News,  XL.,  1879,  pp.  103,  104. 

Tin-  i-.'THTfti.uH  were  found  in  the  feed-tank  of  boilers  at  the  Worthley  Silkstone  Colliery.    They  contained  62.86  per  cent 
of  peroxide  of  iron. 

4.  Aiisted,  David  T 

An  KleiMontary  Course  of  Geology,  Mineralogy,  and  Physical  Geography,  1850,  pp.  277-282. 

5.  Arms,  J.  M 

Canadian  Record  of  Science,  IV.,  Jan.,  1891. 

6.  Biachof,  Gtistav 

Klcmentsof  Chemical  and  Physical  Geology,  Vol.  III.,  1859,  pp.  130-139. 
7    Blatchley,  W.  S. 

Twenty-second  Annual  Report  of  Indiana,  1897  (Dept.  of  Geology  and  Natural  Resources) ;  Clay  Industry,  pp.  105-150; 
I  lii-niii  al  Analyses,  p.  149. 

8.  Bourne.  Edw    E 

History  of  Wells  and  Kennebnnk,  1875,  pp.  119-122. 

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12.  Crosby,  W.  O. 

]>\nainii"il  and  Structural  Geology,  1892,  pp.  270-279. 

13.  Crosby,  W.  O. 

Quartzites  and  Siliceous  Concretions,  Technology  Quarterly,  Vol.  I.,  May,  1888,  p.  397. 

14.  Cuvler,  O. 

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15.  Dana.  James  D. 

Manual  of  Geology,  1863,  1st  ed. ;  Concretionary  Structure,  pp.  96,  626  ;  Origin  of  Concretions,  p.  626  ;  Spherical  an     Flat- 
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16.  Dana,  James  D. 

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17.  Dawson,  Dr.  J.  W. 

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18.  De  la  Beche,  H.  T. 

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19.  Emerson,  Benj    K 

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40  CONCRETIONS   FROM   THE   CHAMPLAIN   CLAYS 

20.  Emmons.  E. 

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21.  Fitton,  Dr.  Wm.  H. 

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Vol.  IV.  (2d  ser.),  pt.  2,  1836,  p.  103. 
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22.  Geikie,  Sir  Archibald. 

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25.  Green,  Alex.  H. 

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55.  Parrot.  Georg  Friedrich. 

Kerherrhe!<   Physiques  sur  les   Pierres  d'Imatra,  Me'm.  1'Acad.  Imp.  des.  Sci.  St.  Peters.,  6th  sc'r.,  Tome  V.,  pt.  2,  1840, 
pp.  297-4-Jfi.   14  pl.s.  anil  map.     (See  Virlet,  73.) 

56.  Penning.  W.  H 

Iron  <  'one-minus  in  Lower  Greensanil  at  Handy,  Bedfordshire,  and  their   Method  of  Formation,  Geological  Magazine,  Vol. 
III.,  Decade  II.,  1876,  pp.  218-220. 

57.  Prestwich,  Joseph 

Geology  ;  Chemical,  Physical,  and  Stratigraphical  Concretions  in  Clays,  Vol.  I.,  1886,  p.  142,  figs  42,  43. 

58.  Ries.  Heiiirlch 

Tin-  I'ltiniate  and   Rational  Analysis  of  Clays  and  their  Relative  Advantages,  Trans,  of  American  Institute  of  Mining 
Kimineers,  New  York,  Atlantic  City  Meeting,  February,  1898. 

59.  Rogers,  Henry  Darwin. 

Concretions,  Geology  of  Penn.,  Vol.  I.,  1858,  pp.  581,  582. 

60.  Rogers.  Henry  Darwin. 

Proc.  of  the  Host.  Soc.  of  Nat.  Hist.,  Vol.  II.,  1845-1848,  pp.  124-130. 
61    Rutley,  Frank 

On  the  Dwindling  and  Disappearance  of   Limestones,  Quart.  Journ.  Geol.  Soc.,  XLIX.,  1893,  pp.  372-382,  PI.  XVIII. 

When  limestones  dwindle  the  result  is  the  production  of  nodnles,  which  the  author  distinguishes  from  those  due  to  concre- 
tionary action  by  calling  them  •'  residual."     lie  hag  made  experiments  on  the  solution  of  cubes,  etc.,  of  chalk,  showing 
how  they  assume  a  rounded  form. 
62.   Safford.  James  M. 

Geology  of  Tennessee,  1 869,  pp.  458,  459. 
63    Scott,  Wm.  B. 

An  Introduction  to  Geology,  1897,  pp.  227,  229,  230,  figs.  86,  87. 

64.  Shaler,  Woodworth,  and  Marbut. 

Glacial  Brick  Clays  of  R.  Land  Southeastern  Mass.,  U.  S.  Geol.  Surrey,  Seventeenth  Annual  Report,  pt.   1,  1895-1896, 
p.  993.     Chas.  D.  Walcott,  Director. 

65.  Sollas.  W    J. 

On  the  Flint  Nodules  of  the  Trimmingham  Chalk,  Annals  and  Mag.  of   Nat.  Hist,  (if,  Voi  VI.,  1880,  pp.  384-395, 
437-461,  Pis.  XIX.,  XX 

66.  Stodder.  Charles. 

Proc.  Bust   Soc.  Nat.  Hint.,  1839,  p.  36V 


42  CONCRETIONS   FROM    THE  CHAMPLAIN    CLAYS. 

67.  Tarr,  Ralph  S. 

Economic  Geology  of  the  United  States,  1894;  Clay  Ironstone,  p.  19;  Concretionary  Action  and  Ore  Deposits,  pp.  80-89, 
fig.  9. 

68.  Tenney,  Sanborn. 

Geology;  for  Teachers,  Classes,  and  Private  Students,  1865,  pp.  205,  206,  figs.  173,  174. 

69.  Thomson,  Sir  C.  Wyville. 

Voyage  of  the  "  Challenger,"  The  Atlantic,  Vol.  I.,  1878,  p.  189. 
Mostly  on  deep-sea  concretions. 

70.  Thomson,  Sir  C.  Wyville. 

Voyage  of  H.  M.  S.  Challenger,  Proc.  Royal  Soc.,  London,  XXIV.,  1876,  pp.  33,  39,  464. 

71.  Todd,  J.  E. 

Log-like  Concretions  and  Fossil  Shores,  American  Geologist,  XVII.,  1896,  p.  347,  PI.  XII. 

72.  Tute,  J.  Stanley. 

On  Some  Singular  Nodules  in  the  Magnesian  Limestone,  Proc.  Yorkshire  Geol.  and  Polyt.  Soc,  Vol.  Xll.,  pt.  3,  1893, 
pp.  245,  246. 

73.  Virlet,  M.  D'Aoust. 

Paper  read  Jan.  20,  1845,  before  Geol.  Soc.  of  France,  Geological  and  Mineral  Pamphlets  (V.),  No.  22. 
Contains  criticism  of  M.  Parrot's  article  (55). 

74.  Walcott,  Charles  D. 

Fossil  Medusae,  U.  S.  Geol.  Survey,  Monographs,  Vol.  XXX.,  1898. 

75.  Watts,  W. 

Singular  Nodules  and  Ice-worn  Stones  found  in  the  Bowlder  Clay  of  Piethorn  Valley,  Trans.  Manchester  Geol.  Soc.,  22, 
1892-1893,  pp.  436-439. 

76.  Wethered,  Edw. 

On  the  Microscopic  Structure  of  the  Wenlock  Limestone,  with  Remarks  on  the  Formation  Generally,  Quart.  Journ.  Geol. 
Soc.,  London,  Vol.  XLIX.,  1893,  pp.  236-246,  PI.  VI. 

77.  White,  C.  A. 

Note  on  Formation  of  Cone-in-Cone,  American  Journal  of  Science  (2),  XLV.,  1868,  pp.  401,  402. 

78.  Winthrop,  John. 

Massachusetts  Historical  Collections  (5),  VIII.,  pt.  4,  p.  138.     Winthrop  Papers. 

79.  Winthrop,  John. 

Selections  from  an  Ancient  Catalogue  of  Objects  of  Natural  History,  found  in  New  England  more  than  One  Hundred  Years 
Ago,  Amer.  Journ.  of  Sci.,  46-17,  1844,  p.  288. 

80.  Woodward,  Henry. 

On  an  Orthopterous  Insect  from  the  Coal  Measures  of  Scotland,  Quart.  Journ.  Geol.  Soc.  of  London,  32,  February,   1876, 
p.  60,  PI.  IX. 

81.  Worthen,  A.  H. 

Rep.  of  the  Geol.  of  Des  Moines  Valley,  Geology  of  Iowa,  Vol.  I.,  pt.  1,  1858,  pp.  190,  191,  201,  215,  216,  226,  227,  236,  242, 

243,  254,  255,  275,  276. 
Fine  figure  of  spherical  concretion. 


INDEX. 


A. 

Adams.  C.  H.,  -Jl. 

Addison,  roncrrtions  of.  21. 

Albiirgh,  concretions  of,  21. 

Alkalies  in  concretion - 

Almond-shaped  concretions.  17 

Aiiilicr-t  Coll"1::' 

Ammonia,  presence  of,  30. 

Analyses  of  ronm-tiuns  'JO,  21,  29-:!l. 

Analyses  of  drift  clays,  20,  22,  29,  :!l. 

Analyses   of    tertiary    marls    and    clays    of    Maltese 

Islands,  22. 

Animal-like  forms,  12,  14,  20,  27  [fig.  115]. 
Answer   to  first  question,   21 ;     to  second    question, 

21-26 ;  to  third  question.  20-35. 
Aragonite,  action  of,  23. 

B. 

Baked  concretion,  20. 
Baker,  C.  Alice,  16. 
Bed,  clay,  12. 
Bi'iit  concretions,  85. 
Bethel,  concretions  of,  21. 
Blatchley,  \V.  S..  •_>•_'. 
Boston  Society  Natural  History,  20,  24. 
Botryoidal  mass,  12. 
Bourne,  Edw.  E.,  19. 
Brattleboro,  11  ;  concretions  of,  20,  27. 
Bridgeport,  20. 

C. 

Cambrian  rocks,  26. 
Canoe  Brook,  17. 

Carbonate  of  lime,  action  of,  21 ;  two  forms  of,  23. 
Carbon  dioxide,  action  of,  22,  25;  amount  of,  29-34. 
Caricatures,  15. 

Cause  of  spherical  concretions,  26. 
Cessation  of  concretionary  process,  25. 
Champlain  clays,  21,  22. 
Chemical  affinity,  24. 
Chesterfield,  11. 
Clay  beds,  conditions  in,  26. 
Clay-dogs,  20. 
Clay  stones,  20,  21. 

Clay,  structure  of,  12,  16,  17,' 22,  26  ;  action  of  carbon 
dioxide  on,  17 ;  analyses  of,  20,  22,  29,  34. 


Club-shaped  concretion,  12. 

Coleman.  Kmma  I.  .  17. 

Compound  concretions.  !.">. 

Concentric  structure,  21. 

Concretionary  structure,  24  ;  theory  of,  21. 

Concretionary  tendency,  24,  27. 

Concretion  in  tin-  process  of  making,  27  ;    analysis  of, 

34. 

Concretions  as  fossil  animals,  19. 
Concretions  as  petrifactions,  19. 
Concretions  formed  subsequently  to  deposition,  25. 
Concretion  with  crescent-shaped  markings,  12. 
Concretion  with  pebble  for  a  nucleus,  24. 
Connecticut  River,  11,  14,  10,  17,  19,  32. 
Constant  characters,  14. 
Cooke,  John  II.,  22. 
Crosby,  W.  O.  22  21. 

D. 

Decomposition  of  feldspathic  rocks,  22. 

Deerfield,  11,  12,  16,  20,  27. 

Deerfield  North  Meadows,  17. 

Deerfield  River,  17. 

Derby,  concretions  of,  21. 

Directions  for  collecting  concretions,  11,  12. 

Disc-shaped  concretions,  13. 

Distorted  folds.  :;:,. 

Double  concretions,  12,  13. 

Dummerston,  11,  17;  concretions  of,  21. 

K. 

East  Bank  concretions.  14,  30 ;   analyses  of,  29,  32,  33. 

East  Deerfield,  16. 

East  Mountain,  16.    • 

East  Windsor  Hill,  11. 

Embedded  concretions,  13,  26,  27. 

Emerson,  B.  K.,  -."•.  35. 

Equipment  for  collecting,  11. 

Kiching  in  hydrochloric  acid,  24. 

Explanation  of  table,  29,  30. 

F. 

Favorable  conditions,  12,  23,  24,  26. 
Flattened  concretions,  cause  of,  26,  27. 
Fossil  meduste,  26. 


44 


INDEX. 


G. 

Gill,  11. 

Glaciers,  action  of,  22. 
Gourd  shaped  concretions,  15. 
Gratacap,  L.  P.,  20. 
Great  River,  16,  27. 
Greenfield,  11. 

H. 

Hadley,  20. 

Hall,  James,  24. 

Hartford,  concretions  of,  11,  16,  20,  27. 

Hinsdale,  11. 

Hitchcock,  Edward,  19,  20,  24,  25. 

Horseshoes,  19. 

Hubbard,  William,  18. 

Humus  acids,  23,  24. 

Hunt,  T.  Sterry,  21. 

Hyams,  Isabel  Finzi,  28. 

Hydrated  silicic  acid,  30. 

I. 

Inland  hill  concretions,  17 ;    analyses  of,  29,  33,  34  ; 

weight  of,  30. 

Inland  hill  from  the  front,  PI.  VIII. 
Inland  hill  from  the  side,  PI.  IX. 

J. 

Jackson,  Arthur  E.,  13. 

J.  Lawrence  Smith  method,  the,  30. 

Joint  planes,  12,  22. 

J  alien,  Alexis  A.,  22. 


K. 


Kennebunk,  18. 
Kimmeridge  clay,  19. 
Kjeldahl  process,  30. 


Literature,  39-42. 
Long  concretions,  15. 


M. 


Manganese  oxide,  action  of,  34. 

Mechanical  pressure,  35. 

Memorial  Association,  concretion  of,  16. 

Method  of  plastering,  15,  16. 

Miniature  canons,  17. 

Montague,  11. 

Moulding  clay,  16,  34  ;  analysis  of,  34. 

Murray,  John,  22. 

N. 

Nichols,  H.  W.,  23,  24. 

Northfield,  11. 

Norwich,  concretions  of,  21. 

Nucleus,  24-26. 


O. 

Oldenburg,  Henry,  19. 

Organic  matter,  25 ;  amount  of,  30. 

Origin  of  concretions,  21,  23-25. 

P. 

Parrot,  M.,  19. 

Part  I.,  11-17. 

Part  II.,  18-42. 

Peculiar  markings,  26. 

Percentage  of  calcium  carbonate  in  concretions,  20,  21. 

Percentage  of  calcium  carbonate  in  surrounding  clay, 

20,  21. 

Percolating  waters,  22-24,  26. 
Perforated  concretion,  14. 
Pine  Hill,  17. 

Pittsford,  concretions  of,  21. 
Plastic  concretion,  27 ;  analysis  of,  34. 
Pocumtuck  Valley  Memorial  Association,  16. 
Process  of  forming  new  rings,  16,  28. 

Q. 

Questions,  three  important,  18. 

R. 

Reasons  for  making  series  of  analyses,  28. 

Reed,  Giles  F.,  17. 

Rice's  Ferry,  11,  14,  16,  32. 

Ritchie,  John,  11. 

River  bank  and  inland  hill  concretions,  28. 

River  bottom  concretions,  15,  28,  30,  32  ;  analyses  of, 

29,  33. 

Rock  Flour,  22. 

Ryegate,  11,  15  ;  concretions  of,  21. 
Rutland  concretions,  21. 

S. 

Sand  beds  and  clay  beds,  26. 

Saw  Mill  River,  11  ;  concretions  of,  12,  24,  25,  28,  34 ; 
analyses  of,  29-31,  33. 

Secondary  modification,  35. 

Series  of  analyses,  28,  29. 

Shaler,  N.  S.,  22. 

Shapeless  masses,  27. 

Shapes  of  concretions,  causes  of,  26-28,  34,  35. 

Sharon,  concretions  of,  21. 

Shelburne,  concretions  of,  21. 

Sheldon,  George,  16. 

Similar  forms  collected  from  one  clay  bed  after  twenty- 
one  years,  13. 

Simple  concretions,  11-15. 

South  Vernon,  27. 

Spherical  concretions,  17  ;  analyses  of,  29,  33. 

Stages  of  growth,  25,  26. 

Stodder,  Charles,  24. 

Stratification,  24,  25  ;  planes  of,  12. 


IM'KX. 


45 


Strui-tun-  uf  rlay,  •_'!'•.  J^ 
Siil.tl.-  force,  L'-J,  24. 
Suiiiinury,  36. 
Sund.Thi'nd,  11,  l:l,  14,20. 

T. 

Tal>lf  showing  quantitative  variations  in  constituents 

of  marls  and  clays,  i'-J. 
Theory  of  concr.-tionarv  striu-tuiv.  -'1. 
Tlin-c  ini|MirUliit  i[Ui'stions,  IS. 
Titanii-  :«-i«l,  'M. 
Tn-lilo  forms,  ll',  13. 
Turtlf,  •-'<>. 
'I'y|>ii:al  concretions,  l-_>. 

u. 

I'lifiiiished  concretions,  27. 
Uniformity  in  coni|Kisition,  31,  32. 
t'ni([ue  concretion,  10. 


V 

Vernon,  11. 

Vt-rtiral  -.M't ion  of  a  concretion,  21. 
Virl.-t,  M.,20. 

\V. 

Walrott.CharlesD.,  26. 
Walk.-r,  John  K,  17. 
\\"at<-li-sliai>ed  concretions,  12. 
U.ii-oii,  Hosa  Holies,  11. 
\VfalliiTin.L,',  L'l-26. 
\Vrij;hU  of  concretions,  80. 
\\Vlls,  18. 

Whitmore's  Ferry,  11,  12,  20. 
Windsor,  concretions  of,  11,  10. 
Winthrop,  John,  18,  19. 
Worthen,  A.  H.,  20. 
Wreath  concretion,  14. 


PLATE   II. 


II 


I.'.' i 


PLATE  III 


14a 


15 


1« 


17 


18 


ao 


PLATE  IV. 


I 


u 


23 


34 


H 


MILIOOI»»*M.H«I»T*VO»I  AMI,  H.  V. 


PI  ATf    V 


31 


I 


PLATE  VI. 


11 


«    I 


37  :- 


Mlftf 


:»y  40 


ti 


PtATE  VII. 


.• 


H 


(Wl 


«3 


64 


•  i. 


MCIIO«IM»M,MA*T  ftVONAftK   N.T. 


PLATE  IX. 


PLATE  X 


71 


74 


7S 


M 


77 


Hll 


M6 


H7 


•JO 


PIATF   XI 


•..1 


M'J 


M 


100 


PLATE  xn. 


in-.' 


I'M 


111.-, 


- 

HIT 


109 


ION 


PLATE   XIII. 


HIP 


111 


111 


114 


113 


115 


XIV. 


117 


HfUOOMAPM.HAftTftVOM  »•>.  M.  V. 


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